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NORTH  AMERICAN  FAUNA 

No.  56 


REVISION 

OF  THE  NORTH  AMERICAN 

GROUND  SQUIRRELS 

With  a  Classification  of  the  North  American 
Sciuridae 


By 
ARTHUR  H.  HOWELL 

Senior  Biologist 

Section  of  Wildlife  Surveys,  Division  of  Wildlife  Research 

Bureau  of  Biological  Survey 


^/V^L 


Issued  by 

UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 
BUREAU  OF  BIOLOGICAL  SURVEY 

Washington,  D.  C.  ApniL  1938 

For  mU  by  xh»  Sup«riDtend«ot  of  Docomenta,  Washington,  D.  C-        -        --         -         -        -        Wo*  ^  ««"»t3 


PUBLICATIONS  in  the  NORTH  AMERICAN  FAUNA  SERIES 


Copies  of  the  North  American  Fauna  not  out  of  print  are  for  sale,  at  the  prices  named, 

by  the  Superintendent  of  Documents,  Government  Printing  Office,  Washington,  D.  C. 

Numbers  marked  with  an  asterisk  [*]  are  out  of  print. 


*No.  1.  Revision  of  the  North  American  Pocket 
Mice.   By  0.  Habt  Mebbiam. 
Pp.  36,  pis.  4.    1889. 

*No.  2.  Descriptions  of  Fourteen   New   Species 
and  One  Nevr  Genus  of  North  American  Mam- 
mals.   By  C.  Habt  Mbbbum. 
Pp.  62,  pis.  8,  figs.  7.    1889. 

*No.  3.  Results  of  a  Biological  Survey  of  the  San 
Francisco  Mountain  Region  and  Desert  of  the 
Little  Colorado,  Arizona.   By  O.  Habt  Mebbiam 
and  Leonhabd  Stejnsgeb. 
Pp.  136,  pis.  14,  maps  6  (colored),  Sgs.  2.    1800. 

*No.  4.  Descriptions  of  Twenty-six  New  Species  of 
North  American  Mammals.   By  O.  Habt  Meb- 
biam. 
Pp.  60,  pis.  3,  figs.  3.    1890. 

*No.  5.  Results  of  a  Biological  Reeonnolssance  of 
South-central  Idaho.  By  C.  Habt  Mebbum  and 
Leonhabd  Stbimbgeb.  Descriptions  of  a  New 
Genus  and  Two  New  Species  of  North  American 
Manunals.   By  C.  Habt  Mebbum. 

Pp.  132,  pis.  4  (1  colored),  figs.  4.    1891. 
No.  6.  Not  iaaued. 

*No.  7.  The  Death  Valley  Expedition:  A  Biological 
Survey  of  Parts  of  California,  Nevada,  Arizona 
and  Utah.  Part  II:  1.  Birds,  by  A.  K.  Fishke. 
2.  Reptiles  and  Batrachlans,  by  Leonhabd  Stbi- 
NEOEB.  3.  Fishes,  by  Chables  H.  Qilbebt.  1.  In- 
secfB,  by  O.  V.  RaET.  6.  MoDusks,  by  K.  E.  C, 
Stb ABN8.  S.  Desert  Trees  and  Shrubs,  by.  C .  Habt 
Mebbum.  7.  Desert  Cactuses  and  Yuccas,  by 
O.  Habt  Mebbiam.  8.  List  of  Localities,  by  T.  S. 
Palmeb. 
Pp.  402,  pis.  16,  maps  6,  figs.  2.    1893. 

*No.  8.  Monograptilc    Revision    of  the    Pocltet 

Gophers,  Family  Geomyi^ae  (exclusive ,  of  the 

species  of  Thomomys).    By  O..Eabi.  Meseium. 

Pp.  258,  pis.  20,  figs.  71,  maps  4  (qoi{ir&d)\   i^[ ,'  ; 

No.  9.  Xot  iuued. 

*No.  10.  Revision  of  the  Shrews  of  the  Amar&an 
Genera  Blarina  and  Notiosorex.  By  C  'Ea&t 
Mebbum.  The  Long-tailed  .Slwews  of  .thp  East- 
em  United  States.  By  QiJ^iifT;  s'.  Miii^^l  ir.. 
Synopsis  of  the  American  Stiir^wa  of  i<bc  ^G^iAr 
Sorex.  By  O.  Habt  Mebbum. 
Pp.  124,  pis.  12,  figs.  3.    1895. 

*No.  11.  Synopsis  of  the  Weasels  of  North  Amer- 
ica.  By  O.  Habt  Mebbum. 
Pp.  44,  pis.  6,  flgs.  16.    1896. 

*No.  12.  The  Genera  and  Subgenera  of  Toles  and 
Lemmings.   By  Qebbit  S.  Milleb,  Jr. 
Pp.  84,  pis.  3,  figs.  40.    1896. 

*No.  13.  Revision  of  the  North  American  Bats 
of  the  FamUy  Tespertillonidae.    By  Qebbit  S. 
MniEE,  Jr. 
Pp.  140,  pis.  3,  figs.  40.    1897. 

*No.  14.  Natural  History- of  the  Tres  Marias  Is- 
lands, Mexico:  General  Account  of  the  Islands 
with  Reports  on  Mammals  and  Birds,  by  £.  W. 

Nelson.  Reptiles,  by  Leonhabd  Stbjnegeb.  Notes 
on  Crustacea,  by  Maby  J.  Rathbun.    Plants,  b^ 
J.  N.  Rose.    Bibliography,  by  E.  W.  Nkison. 
Pp.  97,  pi.  (map),  figs.  2.    1899. 


*No.  15.  Revision  of  the  Jumping  Mice  of  the 
Genus  Zapus.   By  Edwabd  A.  Pbeble. 
Pp.  42,  pi.  1,  figs.  4.    1899. 

*No.  16.  Results  of  a  Biological  Survey  of  Mount 
Shasta,  California.    By  O.  Habi  Mebbiam. 
Pp.  179,  pis.  6,  figs.  46.    1899. 

*No.  17.  Revision  of  American  Voles  ofthe  Genus 
MIcrotus.    By  VERNdN  Bailet.  . 
Pp.  88,  pis.  6,  flgs,  17.    1900. 

*No.  18.  Revision   of  the  Pocket  Mice  of  the 
Genus  Perognathus,   By  Wiltbsd  H.  Osgood. 
Pp.  72,  pis.  4  (Incl.  2  mops),  flgs.  16.    1900. 

*No.  19.  Results  of  a  Biologic  Reconnoissancci 
of  the  Yukon  Region,  ,G^eral  Account  of  th^ 
Region.  Annotated  List  of  Mammals,  by  Wu/- 
FBED  H.  Osgood.    Annotated  List  of  Birds,  by 

Loins  B.  Bishop. 
Pp.  100,pls.7(lncl.  Imap).    1900. 

*No.  20.  Revision  of  the  Skunks  of  the  Genus 
Chincha  [Mephitis].   By  Abthxtb  H.  Howeix. 
Pp.  62,  pis.  8.    1901. 

*No.  21.  Natural  History  of  the  Queen  Charlotte 
Islands,  British  Columbia;  and  Natural  History 
of  the  Cook  Inlet  Region,  Alaska.    By  Wiltbed 
H.  Osgood. 
Pp.  87,  pis.  7  (incl.  1  map),  fig.  (map).    1901. 

*No.  22.  A  Biological  Investigation  of  the  Hudson 
Bay  Region.   By  Edwabd  A.  Pbeble. 
Pp.  140,  Ids.  14  (incl.  1  map).    1902. 

*No.  23.  Index  Generum  Mammalium:  A  List 
of  the  Genera  and  Families  of  Mammals*   By 

T.  S.  Palmeb. 
Pp.984.    1904. 

*No..2,4>.  A  Biol^^cal  Reconnaissance  of  the  Base 
of  tM  .^agkH  Peninsula.  By  Wiltbed  H.  Osgood. 
'    Pp.a5i.p!9,7(incl.  2maps).    1904. 

>*^o.  25.  Biological  Survey  of  Texas:  life  Zones* 
'.   siili  Characteristic  Species  of  Mammals,  Birdsi 
Reptiles,  and  Plants.    By  Vebnon  Bailbt. 
Pp.  2c'?3,.pls.  J6  (Ind.  6  maps),  figs.  24  (ind.  16  maps) . 

■  im^     '  >/  ".. 

'"'No.'26.'Rev)fy4dn  of  the  Skunks  of  the  Genus 
SpUogale.   By  Abthub  H.  Howell. 
Pp.  65,  pis.  10  (Incl.  1  map),    1906. 

No.  27.  A  Biological  Investigation  of  the  Atha- 
basIm-Mackenzie  Region.  By  Edwabd  A.  Pbeble. 
Pp.  574,  pis.  25  (incl.  4  maps),  figs.  16.    1908. 

*No.  28.  Revision  of  the  Mice  of  the  American 
Genus  Peromyscus.   By  Wiltbed  H.  Osgood. 
Pp.  285,  pis.  8  (incl.  1  map),  figs,  12  (maps).    1909. 

*No.  29.  The  Rabbits  of  North  America.   By  E. 

W.  Nelson. 
Pp.  314,  pis.  13,  figs.  19  (ind.  16  maps).    1909. 

*No.  80.  Biological  Investigations  in  Alaska  and 
Yukon   Territory:   1.   East-central   Alaslia;  2i 
OgUvIe   Range,   Yukon;   3.    Macmlllan   River 
Yukon.   By  Wilfbkd  H.  Osgood. 
Pp.  96,  pis.  6  (1  map),  figs.  2  (maps).    1909. 

(.Continued  on  page  S  of  cover) 


NORTH  AMERICAN  FAUNA 


No.  56 


issued     -=^^^^^»L      ^y  '^* 
UNITED  STATES  DEPARTMENT  OF  AGRICULTURE 

BUREAU  OF  BIOLOGICAL  SURVEY 


Washington,  D.  C. 


April  1938 


REVISION  OF  THE  NORTH  AMERICAN  GROUND 
SQUIRRELS,  WITH  A  CLASSIFICATION  OF  THE 
NORTH  AMERICAN  SCIURIDAE 

By  Arthur  H.  Howell,  senior  biologist,  Section  of  Wildlife  Surveys 
Division  of  Wildlife  Research 


CONTENTS 


Introduction .- 1 

Geographic   distribution   of   the    ground 

squirrels.- 2 

Habits  and  economic  relations 4 

Townsend's    ground   squirrel   and   related 

races 5 

Snake  Valley  ground  squirrel 6 

Washington  ground  squirrel 7 

Eichardson's  ground  squirrel 8 

Wyoming  ground  squirrel 10 

Uinta  ground  squirrel 10 

Belding's  ground  squirrel... 11 

Oregon  ground  squirrel. 12 

Columbian    ground    squirrel    and    related 

races... 13 

Parry's  ground  squirrel  and  related  races...  16 

Yukon  Valley  ground  squirrel. 17 

Striped  ground  squirrels 18 

Mexican  ground  squirrels 20 

Spotted  ground  squirrels 20 

Perote  ground  squirrel 21 

Franklin's  ground  squirrel 21 

Rock  squirrels 22 

California   ground    squirrel     and    related 

races 23 

Douglas's  ground  squirrel 27 

Ring-tailed  and  Goldman's  ground  squir- 
rels  28 

Lesser  tropical  ground  squirrel 29 

Antelope  ground  squirrels 29 

Mohave  ground  squirrel 30 

Round-tailed  ground  squirrels. 30 

Mantled  ground  squirrels 31 


Page 
Classification  of  the  North  American  Sciiui- 

dae 34 

Genus  Marmota:  Marmots 37 

Genus  CynoTnys;  Prairie  dogs. — 38 

Genus  Citellm:  Ground  squirrels 39 

Genus  Tamia*;  Eastern  chipmunks 46 

Genus  Eulamias:  Western  chipmunks 47 

Genus  Sciurus:  Tree  squirrels -  48 

Genus  Tamiasciurus:  Red  squirrels 61 

Genus  Microsciurus:  Pygmy  squirrels 51 

Genus  Syntheosciurus:  Pygmy  squirrels 52 

Genus  Glaucomys:  Flying  squirrels 62 

Revision  of  the  genus  Citellus S3 

History  and  nomenclature... — 53 

Generic  and  subgeneric  names 53 

Subgenus  Citellus  Oken 59 

Citellus  townsendii  group 60 

Citellus  uashingtoni  group 69 

Cilettus  Tichardsonii  group 73 

Citellus  panyii  group 85 

Subgenus /c/idoTny*  Allen 106 

Cilelltis  tridecemlineatus  group 106 

CUellus  spilosoma  group —  122 

Subgenus  Poliocitellus,  nobis. 133 

Subgenus  Otospermcphilus  Brandt 135 

Subgenus  NotocUellus,  nobis 162 

Subgenus  Ammospermophilus  Merriam 166 

Subgenus  Xerospermophilus  Merriam 183 

Subgenus  Callospermophilus  Merriam 190 

Fossil  species .-- -  214 

Bibliography 217 

Index 247 


INTRODUCTION 

The  ground  squirrels  of  North  America  now  comprise  97  distinct 
forms  in  31  species.  These  were  arranged  in  the  check  list  of  Miller 
(1924)^  under  the  four  generic  names  Citellus,  Otospermophilus, 
Callospermophilus,  and  AmmosperTnophilus.  For  many  years  there 
has  been  considerable  uncertainty  as  to  the  relationships  of  the 
genera,  subgenera,  and  species.    As  a  result  of  the  present  study,  the 

'  Citations  in  parentheses  refer  to  the  Bibliography,  p.  217. 

154970—38 1  1 

.UPCRINT  Ell  DENT  OF  DOGUWtiS. 


4  r\f\f\ 


2  NORTH  AMERICAN  FAUNA  [No.  56 

ground  squirrels  are  now  grouped  under  a  single  genus,  Gitelltos, 
"which  is  divided  into  eight  subgenera. 

The  material  on  which  the  revision  is  based  is  principally  con- 
tained in  the  collection  of  the  United  States  National  Museum,  in- 
cluding that  of  the  Bureau  of  Biological  Survey.  In  addition,  large 
series  of  specimens  have  been  borrowed  from  several  of  the  larger 
museums  in  the  United  States  and  Canada.^  Altogether  11,724  speci- 
mens have  been  examined  and  identified. 

One  of  the  early  bulletins  of  the  Bureau — that  on  the  Prairie 
Ground  Squirrels,  or  Spermophiles,  of  the  Mississippi  Valley 
(Bailey,  1893) — ^treated  of  the  habits  of  five  of  the  more  important 
species.  Other  writers  have  published  reports  on  the  habits  and 
economic  relationships  of  various  other  species,  notably  that  by 
Grinnell  and  Dixon  (1918)  on  the  Natural  History  of  the  Ground 
Squirrels  of  California. 

The  group  as  a  whole  has  not  been  revised  for  many  years  and 
there  has  been  considerable  uncertainty  as  to  the  relationships  and 
the  proper  allocation  of  many  of  the  species.  This  publication  pre- 
sents the  results  of  a  study  of  the  systematic  relationsliips  and  geo- 
graphic distribution  of  the  American  members  of  the  genus,  with  a 
summary  of  the  known  facts  of  their  life  history,  together  with  a 
critical  study  of  the  systematic  classification  of  all  the  North  Ameri- 
can members  of  the  Sciuridae,  the  family  of  which  the  ground 
squirrels  are  members. 

The  colored  plates  (1  to  11)  here  reproduced  were  made  about  40 
years  ago  for  the  Biological  Survey  from  drawings  by  Ernest  E. 
Thompson,  now  known  as  Ernest  Thompson  Seton,  and  were  printed 
in  expectation  that  a  report  on  the  ground  squirrels  would  soon  be 
issued ;  although  the  revision  for  which  the  plates  were  made  has  been 
long  delayed,  it  is  now  possible  to  present  the  illustrations  in  this 
volume. 

GEOGRAPHIC  DISTRIBUTION  OF  THE  GROUND  SQUIRRELS 

Ground  squirrels  of  the  genus  CiteUus  are  widely  distributed,  both 
in  North  America  and  in  Eurasia.  The  type  species  C.  citelhis, 
ranges  from  Bohemia  eastward  through  the  Union  of  Soviet-Social- 
ist Republics  into  Asia,  and  the  genus,  represented  in  Eurasia  by 
20  or  more  described  species,  occupies  parts  of  southeastern  Europe 
and  central  Asia  eastward  into  Siberia,  Most  of  the  Eurasian 
forms  appear  to  be  quite  distinct  from  those  of  the  New  World,  but 


2  For  the  loan  of  material  used  in  this  study  the  author  extends  thanks  to  the  owners 
and  custodians,  as  follows :  R.  M.  Anderson,  National  Museum  of  Canada ;  F.  Kermode, 
Provincial  Museum  of  British  Columbia  ;  Glover  M.  Allen,  Museum  of  Comparative  Zoology  ; 
Albert  H.  Wright,  Cornell  University ;  H.  B.  Anthony  and  G.  G.  Goodwin,  American 
Museum  of  Natural  History  ;  Witmer  Stone  and  Wharton  Huber,  Academy  of  Natural  Sciences 
of  Philadelphia;  Earl  L.  Poole,  Reading  (Pa.)  Public  Museum;  B.  P.  Bole,  Jr.,  Cleveland 
(Ohio)  Museum  of  Natural  History;  L.  R.  Dice,  University  of  Michigan  Museum  of  Zjology; 
William  L.  Engcls,  University  of  Notre  Dame  ;  W.  H.  Osgood,  Field  Museum  of  Natural  His- 
tory ;  W.  H.  Over,  South  Dakota  Biological  Sui"vey  ;  Myron  H.  Swenk,  University  of  Nebraska  ; 
C.  D.  Bunker,  Kansas  University  Museum  of  Birds  and  Mammals  ;  Frederick  W.  Miller, 
Colorado  Museum  of  Natural  History  ;  Ernest  Morris,  State  Historical  Society  of  Colorado, 
Denver ;  R.  F.  Crawford,  State  College  of  New  Mexico  ;  William  H.  Spaulding,  Montana 
State  College  ;  J.  S.  Stanford,  Utah  State  Agricultural  College ;  Vasco  M.  Tanner,  Brigham 
Young  University  ;  Joseph  Grinnell  and  E.  R.  Hall,  Museum  of  Vertebrate  Zoology  ;  Loye 
H.  Miller,  Los  Angeles  Museum ;  L.  M.  Huey,  San  Diego  Society  of  Natural  History ; 
Chester  Stock,  California  Institute  of  Technology ;  J.  H.  Fleming,  Toronto,  Ontario ; 
C.  B.  Garrett,  Cranbrook,  British  Columbia  ;  P.  F.  Hickie,  Lansing,  Mich. ;  S.  G.  Jewett, 
Portland,  Oreg. ;  E.  T.  Seton,  Santa  Fe,  N.  Mex. ;  William  T.  Shaw,  Fresno,  Calif. ;  Dayton 
Stoner,  Albany,  N.  Y. ;  and  Edward  R.  Warren,  CJolorado  Springs,  (iolo. 


laSS]  REVISION  OF  THE  GROUND  SQUIRRELS  3 

those  from  eastern  Siberia — G.  huxtoni  and  C.  stejnegeri — are  closely 
related  to  the  Alaskan  species  C.  parryii. 

The  North  American  ground  squirrels  occupy  a  large  part  of  the 
continent,  from  the  Arctic  coast  of  Alaska  and  Canada  south  to 
(xuerrero  and  the  valley  of  Mexico.  Being  inhabitants  chiefly  of 
prairies  and  open  mountain  slopes,  they  are  absent  from  the  forested 
regions  of  the  eastern  parts  of  both  Canada  and  the  United  States. 
The  large  ground  squirrels  of  the  Barren  Grounds  {G.  parryii  and 
its  relatives)  range  from  the  shores  of  Hudson  Bay  westward  to 
the  coast  of  Bering  Sea  and  are  found  also  in  eastern  Siberia  and 
on  St.  Lawrence  Island;  the  striped  ground  squirrels  of  the  Missis- 
sippi Valley  {G.  tridecemlineatus)  extend  eastward  to  Michigan 
and  Ohio;  the  gray  ground  squirrel  of  the  prairies  {G.  franklimi) 
reaches  Indiana  in  its  eastward  range,  and  a  colony  introduced  into 
New  Jersey  TO  years  ago  still  survives  there.  Practically  the  en- 
tire area  of  western  North  America,  with  the  exception  of  the  coast 
region  of  Washington  and  a  large  part  of  British  Columbia,  is  oc- 
cupied by  one  or  more  species  of  ground  squirrel. 

In  the  United  States,  ground  squirrels  are  so  abundant  as  to  be 
highly  destructive  to  agricultural  crops.  Their  importance  as  fac- 
tors  limiting  the  profits  of  the  farmer  has  long  been  recognized,  and 
from  its  early  days  the  Biological  Survey  has  been  called  upon  to 
direct  extensive  control  campaigns  in  many  parts  of  the  West. 


North  American  Fauna  No.  56 

United  States  Department  of  Agriculture 

"Revision  of  the  North  American  Ground  Squirrels" 


CORRECTION  SLIP-May  Be  Pasted  at  Foot  of  Page  3 

Actual  date  of  publication,  May  18,  1938 


Page  41,  line  8  from  end:  For  ^2,  read  ^. 

Page  119,  line  1:  For  county  spelling,  read  Moffat. 

Page  146,  line  6  from  end:  For  blank  space  in  parentheses,  insert 41fl- 

54V-59  5'''^  ^°'^'        P^'"^"t^etical  measurements  insert  dMh,  to  read 

Page  162,  last  line  of  section  preceding  Notocitellus :  For  11,  read  1  (San  Pablo 
Page  185,  line  12:   For  34.3,  read  34.9  (skull  length). 


J.  154970—38. 


HABITS  AND  ECONOMIC  RELATIONS 

The  ground  squirrels  of  North  America  differ  from  the  tree  squir- 
rels in  their  habit  of  living  in  burrows  and  most  of  them  become 
dormant  for  periods  of  varying  extent,  in  some  cases  even  more  than 
half  the  year.  During  the  periods  of  estivation  and  hibernation 
there  is  a  decided  drop  in  temperature,  the  respiration  and  blood 
circulation  are  reduced  to  a  minimum,  the  body  becomes  rigid,  and 
the  fat  accumulated  during  the  active  period  is  practically  all  con- 
sumed. Wlien  the  animals  emerge  early  in  spring  they  feed  spar- 
ingly at  first  on  green  vegetation  and  bulbs  of  wild  plants  or  upon 
newly  planted  grain,  if  such  is  at  hand.  During  the  breeding  season, 
wliich  follows  shortly  after  emergence  from  hibernation,  the  desire 
for  green  food  increases  and  the  squirrels  feed  on  growing  grain, 
alfalfa,  wild  herbs,  and  other  succulent  plants.  Early  in  summer, 
as  the  season  of  estivation  approaches,  they  turn  their  attention 
largely  to  the  seeds  of  wild  plants  or  to  ripening  grain ;  after  feed- 
ing for  a  few  weeks  on  such  nutritious  food  they  become  excessively 
fat,  and  are  ready  to  enter  on  their  long  sleep. 

The  fondness  of  certain  of  the  ground  squirrels  for  cultivated 
grain  coupled  with  their  ability  to  increase  rapidly  under  favorable 
conditions,  has  made  them  one  of  the  most  serious  pests  with  which 
the  farmer  has  to  contend.  In  addition  to  destroying  immense 
quantities  of  grain  and  alfalfa,  some  species  are  destructive  to  cul- 
tivated fruits  and  nuts. 

The  burrowing  of  ground  squirrels  on  steep  slopes  frequently  is 
the  initiating  cause  of  soil  erosion,  which  at  times  becomes  serious. 
Grinnell  and  Dixon  (1918,  p.  608),  write  of  the  burrows  of  the  Cali- 
fornia ground  squirrels  as  follows: 

■■'  *  *  their  burrows  are  frequently  the  cause  of  much  destructive  erosion 
on  hillsides  during  heavy  rainstorms.  Numerous  small  landslides  have  been 
noted  on  steep  hillsides  on  the  campus  at  Berkeley,  that  were  plainly  caused 
by  the  presence  of  squirrel  burrows  which  had  concentrated  and  conducted  the 
water  in  narrow  channels  instead  of  permitting  it  to  spread  out  and  soak  in 
or  run  off  in  the  natural  way. 

Ground  squirrel  burrows  are  often  a  serious  menace  to  the  safety 
of  irrigation  systems.  Birdseye  (1912,  p.  13)  tells  of  a  serious 
washout  caused  by  irrigation  water  escaj)ing  through  a  Columbian 
ground  squirrel's  burrow  located  in  an  orchard  on  the  bench  above. 
Lantz  (1918,  p.  14)  cites  the  destruction  of  6  acres  of  alfalfa  caused 
by  the  burrowing  of  a  California  ground  squirrel  into  an  irrigation 
embankment. 

An  additional  count  against  certain  of  the  ground  squirrels  is 
based  on  the  part  they  play  in  the  dissemination  of  diseases  often 
fatal  to  man,  as  is  the  case  with  the  Columbian  ground  squirrel  in 
the  spread  of  spotted  fever,  the  California,  Oregon,  Uinta,  Colum- 
bian, and  Eichardson's  ground  squirrels  in  the  spread  of  bubonic 
plague,  and  the  California  ground  squirrel  and  the  Utah  rock  squirrel 
in  the  spread  of  tularemia. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  5 

The  species  tliat  live  on  deserts  or  in  mountainous  sections  are  of 
little  economic  importance,  since  they  rarely  come  in  contact  with 
agricultural  operations.  This  is  true  of  mantled  ground  squirrels 
(subgenus  Callospermophilus),  antelope  ground  squirrels  (subgenus 
Ammospermophilus) ,  round-tailed  ground  squirrels  (subgenus 
Xerospermophilus) ^  and  spotted  ground  squirrels  {Citellus  spilo- 
soma). 

The  most  serious  damage  to  man's  interests  is  occasioned  by  vari- 
ous species  of  the  typical  subgenus  {Citellus)  and  by  the  rock  squir- 
rels of  the  subgenus  Otospermophilus.  Franklin's  ground  squirrel 
{C.  franklinii)  and  strij)ed  ground  squirrels  {G.  tridecemlineatus 
and  G.  mexicanus)  are  accounted  pests  in  some  sections  by  reason 
of  their  destruction  of  newly  planted  corn  and  garden  vegetables, 
but  this  damage  is  in  part  balanced  by  their  destruction  of  injuri- 
ous insects. 

The  species  that  occasion  the  greatest  damage  to  crops  of  grain, 
and  against  which  extensive  control  operations  have  been  necessary, 
are  the  Columbian  ground  squirrel  (G.  colu7nhianus) ,  Richardson's 
and  Wyoming  ground  squirrels  {G.  richardsonii  richardsonii  and 
G.  r.  elegans)^  Oregon  ground  squirrel  {G.  heldingl  oregGnus), 
Townsend's  ground  squirrel  {G.  townsendii),  Washington  ground 
squirrel  {G.  w ashing t oni) ^  and  Douglas's  and  California  ground 
squirrels  {G.  heecheyi  subspp.). 

Detailed  accounts  of  habits  of  various  species  follow. 

TOWNSEND'S  GROUND  SQUIRREL  AND  RELATED  RACES  =* 

General  hahits. — Townsend's  ground  squirrel  and  related  races 
{Gitellus  townsendii  subspp.)  (pi.  1)  inliabit  dry,  sandy,  sagebrush 
valleys  and  to  a  lesser  extent  juniper-covered  ridges  among  lava 
rocks.  They  live  in  dense  colonies,  digging  their  burrows  under 
the  sagebrush  or  sometimes  out  in  the  open.  A  burrow  dug  out  by 
W.  P.  Taylor,  in  Humboldt  County,  Nev.,  was  found  to  be  about  30 
feet  in  length,  but  only  about  8  inches  below  the  surface.  Of  this, 
Taylor  (1911,  p.  218)  writes: 

A  nest  was  found  in  a  large  spherical  cavity,  so  arranged  that  water  conld 
not  have  gotten  into  it.  Fine  straws  made  np  the  bulk  of  it,  though  white 
cotton  twine  had  been  very  largely  used  to  bind  the  straws  loosely  together. 
A  couple  of  rags,  a  bit  of  rabbit  fur,  some  wool,  and  a  down  feather  were 
also  incorporated  into  the  nest.     Apparently  the  burrows  intercommunicate. 

T.  H.  Scheffer  excavated  a  burrow  of  the  subspecies  G.  t.  town- 
sendii at  Kennewick,  Wash.,  which  had  been  treated  previously 
with  carbon  bisulphide.  The  mother  squirrel  and  seven  young  were 
found  strung  along  the  course  of  the  burrow  two  of  the  latter  in 
the  nest.     Scheffer  (in  manuscript)  describes  the  burrow  as  follows: 

The  runway  descended  rather  steeply  from  the  entrance,  reaching  a  depth 
of  51^  feet  at  distance  of  11  feet  along  the  slope.  From  this  point  a  branch 
ran  downward  to  the  right,  for  about  3  feet  and  ended  in  the  nest  chamber. 
Continuing  slightly  downgrade  to  a  depth  of  6  feet  and  a  distance  of  14  feet 
from  the  entrance,  the  main  tunnel  turned  abruptly  upward  at  an  angle  of 
about  70  degrees  and  reached  the  surface  in  a  partly  obstructed  entrance  12 
feet  from  the  point  where  excavation  was  begun.  From  the  place  of  this  up- 
ward turn  the  main  tunnel  had  been  opened  up  5  or  6  feet  farther  into  looser 

*"  Formerly  known  as  Citellus  vkAUs  subspp.  For  explanation  of  change  of  name  see 
p.  62. 


6 


NORTH  AMERICAN  FAUNA  [No.  56 


earth  from  an  old  badger  digging.  Tliis  material  was  slightly  damp  as  a 
result  of  moisture  penetrating  through  soil  worked  over  by  the  badger  long 
ago. 

The  nest  chamber  was  about  6V2  inches  in  most  dimensions  and  was  located 
just  beneath  the  consolidated  stratum,  its  roof  hollowed  out  in  the  latter.  It 
was  filled  with  a  perfectly  dry  nest  consisting  of  fine,  grass  partly  broken  and 
shredded.  The  two  young  found  suffocated  there  were  concealed  in  the  nesting 
materials. 

Like  other  species  of  their  tribe,  these  ground  squirrels  hibernate 
during  a  good  part  of  the  year — from  July  to  the  following  Febru- 
ary. A  single  individual  was  seen  at  Blalock,  Oreg.,  on  February  1, 
1926;  Scheffer  found  the  squirrels  out  in  numbers  at  Kennewick, 
Wash.,  the  last  week  in  January ;  and  R.  Scott  Zimmerman  reports 
their  appearance  in  Utah  the  latter  part  of  February.  In  the  Ken- 
newick territory  only  a  few  stragglers  were  observed  after  June  20 
and  all  of  these  apparently  were  young.  In  central  Utah,  however, 
a  few  were  seen  as  late  as  September  12  (1932). 

The  young  are  born  early  in  March,  the  litters  numbering  usually 
7  to  10.  Jewett  (1923,  p.  191)  records  taking  a  female  carrying  13 
embryos. 

Although  mainly  terrestrial,  these  little  squirrels  occasionally 
climb  to  the  tops  of  bushes,  where  they  keep  a  sharp  lookout  for  ene- 
mies. Their  voice  is  described  by  Vernon  Bailey  as  "a  fine,  pro- 
longed, chippering  whistle."  Scheffer  (in  ms.)  describes  it  as 
follows : 

The  notes  or  calls  of  this  ground  squirrel  are  very  high  pitched  and  com- 
paratively faint,  not  nearly  so  sharp  and  clear  as  the  chirp  of  a  chipmunk  of 
even  smaller  size.  The  more  prolonged  or  sustained  of  the  two  common  calls 
might  readily  be  mistaken  for  the  faint  trill  of  an  insect,  while  the  clearer, 
chirping  sound  can  scarcely  be  distinguished  from  certain  notes  of  the  horned 
lark.  As  the  little  animal  enters  its  burrow  on  the  nearer  approach  of  sus- 
pected danger,  it  voices  its  final  protest  in  chattering  tones,  faint  but  not 
uncertain. 

Food  habits. — ^Like  most  of  the  ground  squirrels,  this  species  feeds 
mainly  on  green  vegetation  in  the  early  part  of  the  season  and  later 
upon  the  seeds  and  stems  of  grasses  and  other  plants.  Scheffer,  at 
Kennewick,  Wash.,  observed  them  feeding'  on  globemallow  {Sphae- 
ralcea  inunroana)  ^  silver  Indianwheat  (Plantago  purshii),  downy, 
chess  (Bromus  tectoi'um),  slender  wheatgrass  {Agropyron  pauci- 
■flomm),  Indian  ricegrass  {Oryzopsis  hymenoides) .^  and  tumblemus- 
tard  {Norta  altissima),  these  being  the  same  plants  fed  upon  by 
Gitellus  washingtoni  at  Wallula,  on  the  opposite  side  of  the  Columbia 
River.  The  squirrels  have  been  reported  to  feed  also  on  the  leaves 
and  seeds  of  sunflowers  and  the  flowers  of  the  bud  sagebrush  {Arte- 
misia spinescens) .  They  consume  also  grasshoppers,  cicadas,  and 
many  other  insects.  When  in  contact  with  agricultural  crops  they  be- 
come a  serious  pest,  destroying  alfalfa,  wheat,  barley,  potatoes,  beets, 
carrots,  lettuce,  and  other  garden  vegetables.  They  were  reported  in 
1917  to  have  practically  destroyed  a  10-acre  field  of  beets  at  White 
Swan,  Wash. 

EconomiG  status. — This  species  was  found  by  Francis  (1922,  p.  8) 
to  harbor  the  infection  of  tularemia. 

SNAKE  VALLEY  GROUND  SQUIRREL 

The  Snake  Valley  ground  squirrel  {Citellus  idahoetisis)  has  about 
the  same  habits  as  its  near  relative  G.  townsendii  mollis.    The  squir- 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE   1 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  7 

rels  inhabit  the  dry  sagebrush  plains  and  overflow  into  cultivated 
lands,  where  they  prove  destructive  to  crops  of  grain,  alfalfa,  and 
vegetables.  They  are  reported  to  emerge  from  their  hibernating  dens 
in  March,  and  by  the  middle  of  July  they  begin  their  period  of  estiva- 
tion. Each  of  four  females  taken  at  Nampa,  Idaho,  March  12,  con- 
tained small  embryos,  numbering  8,  8,  9,  and  10. 

WASHINGTON  GROUND  SQUIRRELS^" 

General  habits. — ^AVashington  ground  squirrels  {Citellus  washing- 
toni  subspp.)  (pi.  1)  occupy  the  dry  prairies  of  the  Columbia  Basin, 
east  of  the  Colmnbia  Eiver.  Vernon  Bailey  (in  field  notes)  has 
described  their  habitat  as  follows : 

The  country  which  they  inhahit  is  open  and  either  dry  and  sandy,  grassy, 
or  sagebrush  covered.  They  are  most  numerous  along  steep  hillsides,  in 
gulches,  and  in  sagebrush  along  river  bottoms.  On  the  smooth,  grassy  prairie 
they  are  common  and  more  evenly  distributed.  They  collect  where  some  pro- 
tection is  afforded  by  scattered  bunches  of  sagebrush  or  Chriisotharnnus,  but 
avoid  any  dense  cover  from  which  they  cannot  look  out  on  all  sides. 

Bailey  estimated  that  in  the  section  around  Pendleton,  Oreg.,  in 
1896  these  squirrels  averaged  50  to  100  per  acre  in  the  colonies  exam- 
ined. On  a  measured  acre  on  the  prairie  adjacent  to  a  wheatfield  he 
counted  620  burrows  in  addition  to  62  larger  holes  dug  by  badgers  in 
their  search  for  the  ground  squirrels.  The  distribution  of  the  squir- 
rels, however,  is  not  continuous,  and  over  most  of  their  range  they 
are  less  abundant  than  this  estimate  would  indicate. 

A  burrow  of  tliis  species  at  Attalia,  Wash.,  after  having  been 
fumigated  with  carbon  bisulphide,  was  partly  excavated  by  Scheifer, 
who  states: 

At  a  depth  of  4:^-2  feet  and  a  distance  of  11  feet  down  slope  from  the  entrance, 
two  half-grown  squirrels  were  found  suffocated.  At  17  feet  down  slope  from 
the  entrance  the  burrow  had  reached  a  depth  of  hVi  feet,  which  level  it  fol- 
lowed 7  feet  farther— 24  feet  in  all.    No  branch  burrow  or  nest  had  been  found. 

Scheffer  found  the  Washington  squirrels  out  of  their  burrows  at 
Wallula,  Wash.,  on  January  25  (1926).  They  were  oiit  in  numbers 
at  Almota,  Wash.,  on  February  23.  In  mild  seasons,  single  individ- 
uals often  emerge  from  hibernation  as  early  as  January  9.  The  ma- 
jority are  reported  to  enter  estivation  during  July,  but  Scheffer 
found  that  all  had  disappeared  from  their  known  haunts  at  Wallula 
and  Attalia  by  June  16  (1925),  when  the  weather  was  dry  and  hot. 
A  few  were  seen  at  Coulee  City  as  late  as  July  31,  and  one  at  Water- 
ville.  Wash.,  on  August  4.  The  young  are  brought  forth  in  February 
or  early  in  March,  and  by  the  last  of  March  they  are  able  to  run 
about  and  feed  on  ^reen  food. 

The  voice  of  the  Washington  squirrels  is  said  to  be  very  much  like 
that  of  Citellus  townserulii  mollis — a  soft,  lisping  whistle.  When 
their  suspicions  are  aroused,  the  squirrels  stand  up  at  full  length  on 
their  hind  feet  and  give  their  alarm  note  as  they  watch  keenly  for  the 
appearance  of  an  enemy.  The  alarm  is  then  repeated  on  all  sides 
by  other  members  of  the  colony. 

Food  hahits. — Bailey  examined  about  30  stomachs  of  this  species 
at  Pendleton,  Oreg.,  and  found  the  contents  to  be  almost  exclusively 

2i>  Formerly  known  as  Townsend's  ground  squirrel  (Citellus  townsendii).  For  oxpla- 
nation  of  change  of  name  see  p.  70. 


8  NORTH  AMERICAN  FAUNA  [No.  56 

of  vegetable  origin — green  leaves,  plant  stems,  wild  flowers,  bulbs, 
and  seeds.  Seeds  of  alfileria  constituted  over  half  of  the  food  and 
were  found  in  almost  every  stomach.  Insects,  consisting  of  a  large 
caterpillar,  a  few  small  beetles,  and  several  cicadas,  were  found  in 
four  stomachs. 

At  Wallula,  May  22  to  30,  1925,  Scheffer  studied  the  food  habits 
of  the  Washington  squirrels  in  detail,  and  made  the  following  field 
notes : 

Examinations  of  the  stomachs  showed  that  they  were  not  gorged  to  re- 
pletion with  green  stuff  as  they  had  been  earlier  in  the  season,  but  were  filled 
to  a  more  moderate  degree  with  bits  of  succulent  stems,  buds,  seed  pods,  and 
seeds.  Plants  on  which  they  were  observed  to  be  feeding  were  globemallow 
(Sphaeralcea  nmnroana),  silver  Indianwheat  (Plantago  purshU),  downy  chess 
{Bromus  tectorum),  slender  wheatgrass  (Agropyron  pauciflorum) ,  Indian  rice- 
grass  (Orysopsis  hymenoides),  tumblemustard  {Norta  altissima),  and  to  a 
limited  extent,  alfalfa,  oats,  and  wheat.  In  every  case  the  direct  observations 
were  supplemented  by  examination  of  the  plants  on  the  feeding  grounds.  In 
the  case  of  the  grasses  both  heads  and  stems  were  being  used  for  food ;  the 
favored  part  of  the  mallow  seemed  to  be  the  small  circular  seed  vessels,  while 
only  leaf  tissue  of  the  mustard  appeared  to  be  eaten. 

Economie  status. — ^By  reason  of  their  great  abundance  and  their 
fondness  for  grain,  these  ground  squirrels  rank  as  one  of  the  most 
serious  of  agricultural  pests.  They  extend  their  depredations  well 
into  the  fields  of  growing  grain,  cutting  down  the  stalks  and  eating 
only  the  tenderest  portions,  or  at  a  later  stage  selecting  only  the 
fruiting  heads.  In  some  fields,  in  a  strip  around  the  edge  two  rods 
or  more  in  width  they  destroy  more  than  half  the  grain.  They  also 
invade  gardens  and  feed  on  young  cabbage  plants,  green  peas,  and 
young  corn. 

RICHARDSON'S  GROUND  SQUIRREL 

General  habits. — Richardson's  ground  squirrel  {Citellus  richard- 
sonii  richardsonii)  (pi.  2)  lives  on  open  prairies  and  on  flats  along 
the  shores  of  lakes  and  rivers,  seeming  to  prefer  the  sandy  or  gravelly 
ridges.  In  farming  regions,  the  animals  move  into  grainfields  and 
pastures,  and  in  some  localities  they  occur  in  great  abundance. 
Seton  (1928,_p.  261)  describes  a  colony  at  Whitewater,  Manitoba, 
which  he  estimated  to  number  10  squirrels  to  the  acre.  He  states, 
also,  that  at  Carberry,  Manitoba,  in  the  early  eighties,  he  often  noted 
as  many  as  50  on  a  single  acre,  and  captured  20  within  an  hour  in 
two  traps.  At  the  approach  of  an  intruder,  they  stand  flat  on  the 
hind  feet,  the  body  erect  entirely  off  the  ground  and  the  front  feet 
hanging  down  on  the  chest.  This  habit  has  given  the  species  the 
common  name  of  "picket  pin."  When  alarmed  they  whistle  vigor- 
ously and  when  chasing  one  another  they  squeal  loudly.  In  enter- 
ing their  burrows,  after  halting  at  the  entrance  and  lifting  the  head 
to  watch  the  enemy,  they  go  in  head  first  usually  switching  the  tail 
spasmodically.  They  quickly  disappear  with  a  final  flirt  of  the  tail, 
if  danger  still  threatens. 

James  Silver  excavated  and  measured  nine  burrows  of  this  species 
in  North  Dakota  and  found  that  the  tunnels  varied  in  length  from 
about  12  to  49  feet  and  in  depth  below  the  surface  from  3  feet  10 
inches  to  5  feet  8  inches.  Most  of  these  burrows  contained  a  cavity 
6  to  9  inches  in  diameter  in  which  was  a  nest  made  of  dry  or  green 
grass,  straw,  and  oat  hulls. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture.  Biological  Survey 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  9 

Apparently  the  dates  of  entering  and  leaving  the  hibernation  dens 
vary  considerably  with  local  conditions.  Ranchers  in  central  Mon- 
tana reported  the  squirrels  as  appearing  in  February,  and  Seton 
(1928,  p.  264)  quotes  A.  S.  Barton  in  the  statement  that  these  squir- 
rels came  out  during  February  (1905)  in  the  country  around  Boisse- 
vain,  Manitoba.  At  Cando,  N.  Dak.,  they  were  first  observed  in 
1915  on  March  10.  In  Alberta,  on  April  6,  1920,  Francis  Harper 
noted  them  in  numbers  at  many  points  along  a  railroad  between 
Calgary  and  Wetaskiwin. 

In  North  Dakota,  practically  all  the  adults  go  into  estivation  in 
July,  while  the  young  remain  above  ground  until  September  or  later. 
At  Waterton  Lake,  Mont.,  August  14,  1917,  Vernon  Bailey  noted 
many  burrows  of  this  species  but  only  a  single  animal,  and  thought 
that  most  of  them  had  estivated  on  account  of  the  drying  up  of  the 
vegetation.  At  St.  Mary  Lakes,  Mont.,  they  were  numerous  and  ac- 
tive on  August  24.  At  Bismarck,  N.  Dak.,  most  of  the  squirrels  had 
denned  up  by  September  1,  but  at  Blackfoot,  Mont.,  they  were  still 
numerous  above  ground  on  September  12,  and  at  Van  Hook,  N.  Dak., 
on  October  16,  one  was  seen  out  after  a  very  cold  night. 

K.  F.  Ebner,  of  Cando,  N.  Dak.,  made  notes  on  the  disappearance 
of  these  squirrels  in  the  fall  of  1914;  he  stated  that  during  the  sec- 
ond week  in  September  they  appeared  only  on  pleasant  forenoons, 
and  if  disturbed  would  go  into  holes  and  remain  the  rest  of  the  day ; 
that  after  about  October  1,  they  would  remain  in  their  burrows  for 
2,  3,  and  sometimes  4  days  in  succession,  even  in  pleasant  weather; 
and  that  none  were  seen  from  October  15  to  November  2,  but  on  the 
latter  date  they  were  unusually  lively  in  the  pasture. 

Richardson's  squirrels  produce  but  one  litter  a  year,  numbering 
from  6  to  11,  with  an  average  of  7.5.  The  period  of  gestation,  as 
determined  by  U.  S.  Ebner,  from  specimens  kept  in  captivity,  is 
about  28  to  32  days.  The  young  squirrels  appear  above  ground  at 
various  times  from  April  20  to  June  1.  Ebner  dug  out  a  number  of 
burrows  in  fall,  without  finding  any  store  of  food. 

The  voice  of  this  species  is  described  as  a  short,  shrill,  whistling 
note.  The  animals  are  ordinarily  not  suspicious,  and  when  taken 
young  some  make  gentle  and  attractive  pets,  while  others  remain 
wild  and  vicious. 

Food  hahits. — On  the  prairies,  these  squirrels  subsist  on  the  native 
grasses  and  flowering  plants.  They  consume  also  seeds  of  various 
plants,  including  bindweed  and  sagebrush,  and  capture  many  grass- 
hoppers and  caterpillars.  Grainfields  attract  them  and  there  they 
destroy  quantities  of  grain,  both  in  narrow  strips  along  the  edges 
and  also  around  their  burrows  in  the  middle  of  the  field.  Follow- 
ing planting  they  dig  up  and  eat  the  seed  grain.  Early  in  the  sea- 
son they  cut  off  and  eat  the  succulent  stems,  and  when  the  grain  is 
ripening  they  pull  down  the  stalks  and  cut  off  the  heads. 

Seton  (1928,  p.  270)  tells  of  finding  in  the  pouches  of  one  of  these 
ground  squirrels  240  grains  of  wheat  and  nearly  1,000  grains  of 
wild  buckwheat.  He  records  also  finding  about  2  quarts  of  sprouted 
wheat  in  a  squirrel's  den  that  had  been  raided  by  a  badger  in  fall. 


II Q  NORTH  AMERICAN  FAUNA  [No.  56 

WYOMING  GROUND  SQUIRREL 

General  habits.— The  Wyoming  ground  squirrel  {Gitellus  richard- 
sonii  elegans)  inhabits  the  sage  and  greasewood  plains,  chiefly  in 
the  Transition  Zone  and  partly  in  the  Upper  Sonoran.  The  annuals 
reach  comparatively  high  elevations  in  sections  where  grass-covered 
flats  occur  on  a  gravelly  soil,  but  in  general  they  avoid  wooded  or 
brush-covered  areas.  In  many  localities  their  burrows  cover  the 
ground  more  thickly  than  prairie  dog  mounds,  and  the  population 
has  been  estimated  to  average  at  least  20  squirrels  to  the  acre.  The 
burrows  are  usually  more  numerous  bordering  cultivated  fields,  or 
in  grassy  patches  in  the  semidesert  regions.  In  irrigated  districts, 
these  squirrels  concentrate  in  large  numbers  along  roadways,  railway 
embankments,  and  irrigation  ditch  banks,  where  the  burrows  are 
safe  from  the  irrigation  waters. 

In  the  Green  River  Basin,  Wyo.,  the  first  of  these  squirrels  to 
emerge  from  hibernation  were  reported  on  April  2,  and  by  April  12 
they  were  out  in  great  numbers.  A  female  taken  at  Opal,  Wyo., 
April  21,  contained  5  small  embryos.  Burnett  (1920,  p.  8)  records 
that  14  females  examined  in  1916  had  an  average  of  8.2  young,  and 
19  examined  in  1920  an  average  of  4,6.  He  states  that  the  young 
are  born  about  the  middle  of  May.  By  the  middle  of  August  the 
squirrels  are  fat  and  ready  to  begin  their  long  sleep  underground. 
Bailey  reports  that  at  Meeker,  Colo.,  most  of  the  ammals  had  gone 
into  winter  quarters  by  August  10,  though  several  were  seen  on 
August  12.  At  Lay,  Colo.,  A.  G.  Wallihan  reports  that  they  retire 
about  the  middle  of  July. 

Food  habits. — Stomachs  of  5  adults  examined  at  Elk  Creek,  Idaho, 
were  largely  filled  with  ripe  fruit  of  Amelanchier  alnifoUa,  together 
with  green  foliage,  flowers  of  a  composite,  seeds  of  grasses,  and  a 
few  remains  of  grasshoppers.  Two  individuals  taken  in  the  Laramie 
Mountains,  Wyo.,  had  their  stomachs  filled  with  the  blossoms  of 
rabbitbrush  (Ohrysothamnus) ,  and  one  taken  at  Cheyenne  had  its 
pouches  full  of  the  heads  of  grama  grass.  A  specimen  of  C.  r.  neva- 
densis  taken  in  Malheur  County,  Oreg.,  had  its  pouches  filled  with 
1,160  fruiting  capsules  with  seeds  of  Collomia. 

Economic  status. — ^Wherever  these  ground  squirrels  come  in  con- 
tact with  agricultural  operations  they  become  a  serious  pest.  They 
consume  large  quantities  of  range  grasses  and  in  grainfields  pull 
down  the  stalks  and  consume  the  heads  of  grain.  They  are  especially 
destructive  to  growing  barley  and  oats.  Ranchmen  in  Moffatt 
County,  Colo.,  claimed  that  in  1906  this  species  destroyed  fully  a 
third  of  the  local  rye  crop  and  that  they  ruined  a  5-acre  field  of 
oats  in  the  same  county.  Carrots,  radishes,  lettuce,  and  other  garden 
crops  are  sometimes  damaged  by  these  squirrels.  Near  Laramie, 
Wyo.,  a  promising  head-lettuce  industry  was  threatened  when  the 
squirrels  nibbled  into  the  growing  heads  and  so  deformed  them  that 
an  imperfect  product  resulted.  Plague  infection  was  demonstrated 
in  a  specimen  of  this  squirrel  taken  in  1935  near  Dillon,  Mont. 
(Meyer,  1936,  p.  964). 

UINTA  GROUND  SQUIRREL 

General  habits. — ^The  Uinta  ground  squirrel  {Gitellus  armatus) 
occupies  dry  meadows,  pasture  lands,  and  cultivated  fields  in  high 


i 


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valleys,  and  ranges  in  the  mountain  meadows  nearly  to  timber  line 
(Wind  River  Mountains,  Wyo.,  10,500  feet).  The  animals  seem  to 
prefer  moist  locations  near  water,  especially  where  the  vegetation 
is  rank.  They  live  in  large  colonies  in  burrows  dug  in  soft  soil  in 
the  meadows  or  along  irrigation  ditches.  Occasionally  they  climb 
into  bushes.  Their  voice  is  said  to  be  louder  than  that  of  C.  elegans; 
their  call  is  described  by  Merritt  Gary  as  "a  sharp,  vibrant,  bird-like 
Avhistle,  often  terminating  in  a  trill."  According  to  O.  E.  Stephl, 
they  have  another  call,  consisting  of  three  distinct  notes,  repeated 
rather  slowly.  Like  some  others  of  their  tribe,  they  spend  only 
about  5  months  of  the  year  above  ground,  the  remaining  period 
being  spent  in  estivation  and  hibernation.  In  Yellowstone  Park, 
nearly  all  the  adults  disappear  by  the  middle  of  August  and  by  the 
end  of  that  month  only  an  occasional  immature  individual  is  seen 
above  ground.  A  very  late  record  is  that  of  a  specimen  collected 
at  Mammoth  Hot  Springs,  Yellowstone  Park,  October  4  (1902). 
The  first  to  come  out  in  spring  appear  usually  from  about  April  5 
to  11,  though  occasionally  one  may  be  seen  as  early  as  March  17. 

Food  habits. — Little  of  a  definite  nature  is  on  record  concerning 
the  food  habits  of  this  species,  but  reports  of  field  collectors  show 
that,  like  other  related  species,  these  ground  squirrels  feed  on  green 
vegetation  and  dry  seeds.  Stomachs  of  10  specimens  examined  by 
A^ernon  Bailey  in  Star  Valley,  Wyo.,  were  full  of  green  herbage, 
flowers  of  rabbitbrush  {Chrysothamnus) ,  and  seeds  of  grasses  and 
other  plants.  Two  contained  some  golden  currants  (Rlbcs  aureum) . 
That  these  squirrels  relish  meat  is  evidenced  by  Bailey's  statement 
that  they  ate  two  pocket  gophers  caught  in  his  traps. 

Living  chiefly  in  mountainous  country,  the  Uinta  ground  squirrels 
come  in  conflict  with  agricultural  interests  less  frequently  than  do 
many  of  the  other  species,  but  wherever  their  range  extends  into 
cultivated  valleys,  they  damage  crops  to  some  extent.  Plague  has 
been  demonstrated  in  specimens  of  this  squirrel  taken  in  Bonneville 
County,  Idaho,  in  1936  (Meyer,  1936,  p.  965). 

BELDING'S  GROUND  SQUIRREL 

General  habits. — Belding's  ground  squirrel  {Citellus  beldingi 
beldingi)  (pi.  3)  inhabits  mountain  meadows  near  timber  line  in  the 
Sierra  Nevada  and  is  only  rarely  found  in  open  timber  or  brush  lands. 
Their  burrows  are  dug  beneath  stumps,  logs,  or  rocks,  or  sometimes 
out  in  an  open  meadow,  and  frequently  they  appropriate  the  tunnels 
of  pocket  gophers  {Thomomys)  for  their  own  use.  The  period  of 
hibernation  in  this  species  is  not  definitely  known  but  evidently  in 
the  high  mountain  meadows  these  squirrels  are  able  to  obtain  an 
abundance  of  green  food  all  summer  and  consequently  they  remain 
active  considerably  longer  than  do  other  species  living  in  the  dry 
valleys  at  lower  altitudes.  Grinnell  and  Dixon  (1918,  p.  6G4)  report 
these  squirrels  numerous  in  Tioga  Pass,  Calif.,  on  September  28  and 
some  out  as  late  as  October  7  near  Ten  Lakes,  Yosemite  Park.  At 
Lake  Tahoe,  J.  A.  Loring  found  them  out  in  numbers  on  May  18. 
Grinnell  and  Storer  (1924,  p.  173)  mention  a  specimen  obtained  at 
the  Farrington  ranch,  near  Williams  Butte,  on  April  29,  1916.  The 
young  are  born  about  the  first  of  July. 


12  NORTH  AMERICAN  FAUNA  [No.  56 

The  voice  of  this  species  is  said  to  resemble  that  of  the  Oregon 
ground  squirrel,  according  to  Grinnell  and  Dixon  (1918,  p.  662) — 

The  usual  call  of  warning  consists  of  a  series  of  from  five  to  eight  short 
shrill  whistles  uttered  in  quick  succession  and  weakening  toward  the  last. 
F'emales  warn  their  young  when  foraging  abroad  with -a  lower-pitched,  double 
note,  or  bark,  e-chert.    A  single  note,  sirt,  is  also  frequently  heard. 

Food  hahits. — Belding's  ground  squirrel  feeds  largely  on  the  stems 
and  seeds  of  wild  grasses.  C.  Hart  Merriam  reports  the  species 
eating  the  flowers  of  beardtongue  {Pentstemon  confertus).  Edmund 
C.  Jaeger  (1929,  p.  91),  writing  of  these  squirrels  as  observed  in 
July  near  Bishop  Pass,  Calif.,  says : 

Their  principal  food  at  this  time  was  the  half-ripe  seeds  of  a  phacelia,  the 
fruit  of  which  was  borne  on  stout  stems  about  seven  inches  from  the  ground. 

In  Long  Valley,  Mono  County,  A.  Brazier  Howell  (1924,  p.  33) 
found  them  feeding  extensively  on  a  species  of  cicada  {Okanagana 
magnifica) .  C.  Sharsmith  (1936,  p.  12)  records  instances  where  these 
squirrels  had  killed  a  junco,  an  Audubon  warbler,  and  a  chipmunk. 
Since  the  range  of  Belding's  squirrel  lies  above  the  zone  of  agricul- 
ture, the  animal  is  of  no  special  economic  importance. 

OREGON  GROUND  SQUIRREL 

General  habits. — ^The  Oregon  ground  squirrel  {Citellus  heldingi 
oregonus)  lives  chiefly  in  mountain  meadows  but  also  in  pastures, 
meadows,  and  grainfields  in  the  valleys,  and  to  a  less  extent  in  open 
pine  forests.  It  avoids  marshy  ground  as  well  as  rocky  or  brushy 
slopes.  It  lives  in  large  colonies,  especially  on  ranches  where  food  is 
abundant.  Ira  N.  Gabrielson  reports  a  count  of  466  on  a  2-acre 
tract  in  Klamath  County,  Oreg.  On  a  ranch  in  Butte  Valley,  Calif., 
Grinnell  and  Dixon  (1918,  p,  654)  estimated  560  burrows  on  1  acre. 
One  burrow  they  excavated  was  66  feet  long,  including  the  various 
windings  and  its  branches ;  its  greatest  depth  below  the  surface  was 
45  inches. 

These  squirrels  are  almost  exclusively  ground  dwellers ;  very  rarely 
have  they  been  observed  to  climb  into  bushes  to  obtain  seeds.  Their 
voice  is  described  by  Bailey  as  "a  rattling  chipper.,  or  series  of  sharp 
chips  so  rapidly  uttered  that  they  almost  blend  into  a  prolonged 
trill." 

Hihernation. — The  Oregon  ground  squirrel  spends  more  than  half 
the  year  in  a  dormant  condition.  The  date  of  entering  hibernating 
quarters  varies  with  the  dryness  of  the  summer  and  the  supply  of 
green  vegetation.  During  some  seasons,  in  the  valleys,  most  of  the 
squirrels  disappear  by  July  10,  but  in  seasons  of  greater  rainfall  they 
remain  out  several  weeks  longer;  in  the  mountains,  small  numbers 
may  be  seen  above  ground  as  late  as  the  first  of  September.  In 
spring  they  begin  to  appear  about  the  middle  of  February  and  by 
the  first  week  in  March  are  usually  out  in  force,  even  if  obliged  to 
burrow  through  a  foot  or  more  of  snow  to  reach  the  surface.  At 
low  altitudes  in  Umatilla  County,  Oreg.,  some  have  been  reported 
out  as  early  as  January  22. 

Breeding. — This  species  produces  one  litter  of  young  a  year,  vary- 
ing in  number  from  4  to  12,  with  an  average  of  about  8.  The  young, 
born  about  April  10  to  20,  appear  above  ground  about  May  10.  In 
Butte  Valley,  Calif.,  on  May  16,  Grinnell  and  Dixon  (1918,  p.  658) 
report  young  out  of  the  burrows  in  numbers,  all  about  one-fourth  to 
one-third  grown. 


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Food  hahits. — The  food  of  the  Oregon  ground  squirrel  consists 
mainly  of  green  vegetation.  In  addition  to  grasses  and  cultivated 
grain,  the  following  plants  have  been  identified  in  the  stomachs  or 
cheek  pouches :  Flowers,  stems,  and  leaves  of  camas  ( Quamasia  qua^ 
mash)^  buttercup  {Ranunculus)^  springbeauty  {Claytonia),  shoot- 
ingstar  {Dodecatheon) ^  mule-ears  (Wyethia  atnpIexicauJis) ,  sage- 
brush, and  alfileria.  Grasshoppers,  crickets,  and  other  insects  are 
eaten  by  the  squirrels,  and  18  caterpillars  from  one  stomach  were 
recorded  by  Bailey.  The  squirrels  have  been  reported  to  catch  and 
kill  young  chickens  and  to  devour  their  own  kind  found  caught  in 
traps. 

Economic  status. — Grinnell  and  Dixon  consider  this  species  second 
in  economic  importance  in  California  to  the  California  ground  squir- 
rel; they  point  out  that  these  squirrels  occur  in  great  abundance  in 
the  grasslands  and  do  serious  damage  to  range  grasses.  Also,  in 
some  sections,  they  inhabit  fields  of  alfalfa  and  grain — wheat,  oats, 
and  r3'e — and  destroy  a  large  proportion  of  the  crops. 

This  species  has  in  recent  years  been  found  to  carry  bubonic  plague. 
Surveys  made  during  the  summer  of  1934  in  Modoc  County,  Calif., 
resulted  in  finding  the  disease  in  5  percent  of  the  squirrels  shot  or 
found  dead  in  an  area  of  65,000  acres.  In  April  1935,  plague  was 
proved  in  107  Oregon  ground  squirrels  (7  percent  of  1,492  squirrels 
shot)  in  Modoc  County.  A  fatal  case  of  human  plague  occurred  at 
Lakeview,  Oreg.,  in  May  1934,  probably  contracted  from  a  ground 
squirrel  of  this  species  (Meyer,  1936,  p.  964) . 

COLUMBIAN  GROUND  SQUIRREL  AND  RELATED  RACES 

General  hahits. — The  Columbian  ground  squirrel  and  related  races 
{Gitellus  columhianus  subspp.)  (pi.  4)  live  in  a  wide  variety  of 
habitats,  from  the  open  prairies  of  eastern  Washington  to  the  moun- 
tain parks  at  an  altitude  of  7,000  or  8,000  feet.  Apparently  the 
animals  prefer  rough,  rocky,  half-forested  hillsides,  but  in  many 
places  they  are  numerous  in  hay  meadows,  grainfields,  stony  pastures, 
and  open  pine  flats.  They  live  in  colonies  but  are  somewhat  less 
gregarious  than  prairie  dogs.  They  spend  the  greater  part  of  the 
daylight  hours  gathering  and  consuming  food  from  an  area  rather 
close  about  their  burrows,  seeking  safety  in  their  dens  when  danger 
appears,  but  if  the  food  supply  is  limited  near  their  dens,  they  often 
make  somewhat  extended  trips  in  search  of  some  favorite  item. 

These  squirrels  are  rather  noisy,  and  in  a  colony  their  alarm  note — 
a  clear,  sharp  chirp.,  repeated  a  number  of  times — is  almost  con- 
stantly heard  from  sunrise  to  sunset.  In  places  where  they  are  per- 
secuted by  man  and  also  in  wilderness  areas  remote  from  civilization 
they  are  usually  shy  and  are  difficult  to  approach  closely.  When 
given  protection,  however,  as  in  some  of  the  national  parks,  they 
become  so  tame  that  they  will  take  food  from  the  hand. 

Burrows  and  nests. — The  burrows  of  these  squirrels  are  dug  be- 
neath logs,  stumps,  or  boulders  and  descend  at  an  angle  of  about  45°. 
Vernon  Bailey  (1918,  p.  47)  describes  a  summer  den  that  he  ex- 
cavated near  Piegan  Pass,  at  7,000  feet  altitude  in  Glacier  National 
Park,  Mont.,  as  follows : 

The  mound  at  the  entrance  of  the  burrow  contained  about  4  bushels  of  earth 
and  stones  brought  from  the  burrow,  and  the  lower  part  was  packed  and  hard  as 
though   an   accumulation   of  several   years.     Tliere   were   two   other   openings 


14 


NORTH  AMERICAN  FAUNA  [No.  56 


farther  back  from  which  no  earth  had  been  thrown  and  evidently  they  had  been 
tunneled  to  the  surface  from  below.  The  main  shaft  of  the  burrow  was  usually 
3  or  4  inches  in  diameter,  and  back  a  couple  of  feet  from  the  entrance,  just 
before  the  burrow  forked  into  two  main  shafts,  was  a  roomy  chamber  where 
the  squirrels  could  turn  around  and  sit  up  comfortably,  a  sort  of  reception 
room.  Near  secondary  forks  were  also  two  other  chambers  which  may  have 
served  several  purposes,  such  as  convenience  in  storing  earth  brought  out  of 
the  tunnels,  or  places  of  retreat  from  which  to  watch  for  enemies  that  might 
enter  the  burrow  from  either  direction.  Well  back  about  8  feet  from  the 
entrance  and  a  foot  below  the  surface  of  the  ground  was  a  large  nest  chamber 
about  a  foot  in  diameter  nearly  filled  with  old  soft  nest  material.  The  nest 
was  composed  almost  entirely  of  the  soft  flat  leaves  of  the  brown  "glacier 
grass"  (Juncoidcs  parviflorum)  which  abundantly  covers  the  mountain  slopes. 
At  the  bottom  it  was  damp  and  moldy,  but  from  the  bed  in  the  center  to  the 
top  it  was  dry  and  clean,  and  a  few  fresh,  green  blades  had  been  brought  in 
for  food  or  nest  material.  It  had  evidently  served  as  winter  quarters  for  the 
old  squirrel  and  as  a  nest  for  her  young  and  was  being  prepared  for  the  coming 
winter.  From  one  side  of  the  nest  chamber  the  burrow  led  down  to  an  older 
and  deeper  chamber  of  some  previous  year,  containing  at  the  bottom  an  old 
rotten  nest  half  full  of  excrement.  A  tunnel  ran  from  it  back  toward  the  main 
entrance  and  into  the  main  tunnel  near  the  middle,  making  an  easy  way  of 
escape  if  an  enemy  should  dig  to  the  first  nest.  Back  of  the  nest  a  small  shaft 
led  to  the  surface  of  the  ground  and  another  opened  out  at  the  end  of  the  first 
main  fork  of  the  tunnel.  These  rear  openings  were  half  concealed  in  the  grass 
and  evidently  were  for  use  as  avenues  of  escape  in  case  the  burrow  should  be 
entered  by  a  weasel  or  dug  out  by  bear  or  badger. 

Estivation  and  hibernation. — This  species  spends  from  Y  to  8 
months  annually  in  a  dormant  condition.  Those  individuals  living 
in  the  valleys  and  on  the  prairies  become  very  fat  by  midsummer, 
and  from  July  15  to  30  a  noticeable  decrease  in  their  numbers  is  ob- 
served as  some  of  them  enter  estivation.  In  eastern  "Washington,  in 
dry  seasons  by  July  29  and  in  wet  seasons  by  August  11,  all  have 
entered  their  dens  for  the  long  sleep  (Shaw,  1925a,  p.  75).  These 
squirrels  do  not  as  a  rule  drink  water,  but  depend  upon  succulent 
vegetation  to  supply  needed  moisture.  Apparently  the  date  of  be- 
ginning estivation  is  determined  chiefly  by  the  ripening  of  the  vege- 
tation and  consequent  reduction  of  the  moisture  content  in  their  food, 
and  in  part  also  by  the  accumulation  of  fat  in  the  body. 

At  Osborn,  Idaho,  the  last  of  the  ground  squirrels  disappeared 
following  a  first  frost  on  August  8  (1895) .  In  the  Bitterroot  Valley, 
Mont.,  all  had  begun  estivation  by  August  25  (1909).  In  the  moun- 
tains, at  higher  altitudes,  some  of  the  animals  remain  out  until  the 
first  week  in  October  (Woodman  Creek,  west  of  Lo  Lo,  Oct.  7) .  A 
single  individual  was  taken  near  Kalispell,  Mont.,  on  October  1 
(1932). 

At  Pullman,  Wash.,  the  first  squirrels  came  out  of  their  hiberna- 
tion dens  on  February  21  (1913),  March  1  (1912),  and  March  8  (1911 
and  1917).  At  Endicott  and  St.  Johns,  Wash.,  they  first  appeared 
from  February  2  to  9  (1909).  In  the  Bitterroot  Valley,  Mont.,  the 
first  were  seen  on  March  6  (1910),  and  March  25  (1912),  and  by 
March  31  they  were  out  in  full  numbers. 

The  hibernation  dens  have  been  studied  and  described  by  W.  T. 
Shaw  (1925b,  fig.  2,  opp.  p.  58),  who  states: 

A  hibernation  den  is  frequently  a  part  of  an  ordinary  den  shut  or  sealed  off 
from  the  main  den  by  having  all  connecting  burrows  very  effectiially  plugged. 
It  may,  however,  be  quite  remotely  hidden  away  from  the  large  summer  den. 

Of  50  hibernation  cells  measured,  the  average  depth  below  the 
surface  was  found  to  be  2  feet  6  inches;  the  shallowest  cell  was  6 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  15 

inclies  below  the  surface,  the  deepest  4  feet  11  inches.  Occupied 
dens  are  sealed  by  the  squirrels  with  a  plug  of  earth  2  feet  or  more 
in  length,  tamped  in.  For  most  of  the  hibernation  dens  (except 
those  on  a  side  hill)  drainage  is  provided  to  carry  water  away. 
In  some  cases  an  exit  shaft  leading  toward  the  surface  is  provided. 
When  ready  to  come  out  in  the  spring  the  animal  digs  its  way  to  the 
surface,  placing  the  soil  removed  in  the  bottom  of  the  burrow,  thus 
leaving  no  loose  dirt  at  the  entrance. 

Storage  of  food. — Food  supplies  are  stored  in  the  hibernation  dens 
to  a  limited  extent.  Regarding  this  habit,  Shaw  (1925b,  fig.  11,  opp. 
p.  79)  writes  as  follows: 

Very  unexpected  iufonnatiou  has  been  found  in  connection  with  the  matter 
of  the  food  supply  being  stored  for  the  winter.  The  nests  of  female  and  imma- 
ture squirrels  are  almost  without  exception  lacking  in  a  store  of  food.  The 
uests  of  the  old  males,  on  the  other  hand,  very  frequently,  though  not  always, 
have  a  cache  of  some  kind  of  food.  Strange  to  say,  in  this  stored  supply 
they  seem  to  prefer  some  wild  seed  or  bulb  to  grain,  and  nests  found  in  wheat 
fields  are  frequently  stored  with  some  wild  seed.  Furthermore,  they  usually 
use  but  the  one  kind  of  seed,  or  bulb,  in  a  nest  at  a  time,  though  several  kinds 
of  seeds  and  bulbs  have  been  found  in  the  various  uests  discovered.  In  this 
connection  it  is  interesting  to  note  that  the  old  male  squirrels  appear  a  week 
to  10  days  before  the  females  and  immature,  often  when  the  weather  is  bad 
and  food  scarce,  hence  the  need  of  food.  It  is  also  of  interest  to  note  that  the 
store,  which  is  found  in  the  mulch  or  bottom  of  the  nest,  seems  not  to  be 
touched  during  the  winter,  as  several  interesting  observations  tend  to  show, 
but  is  reserved  until  the  time  of  awakening  in  the  spring. 

Breeding. — The  number  of  young  in  a  litter  varies  from  2  to  5, 
rarely  7,  averaging  about  3.5.  The  gestation  period,  as  determined 
by  Shaw  (1925d,  p.  108)  from  animals  kept  in  captivity  under  semi- 
natural  conditions,  is  24  days.  The  rutting  season  begins  about 
March  15  to  20,  and  Shaw  records  capture  of  a  wild  adult  at  Pullman, 
Wasli.,  on  April  6,  carrying  G  fully  formed  embryos.  At  Ford, 
Idalio,  James  Silver  examined  25  females  on  April  10  that  were 
carrying  large  embryos ;  on  April  IG,  13  females  showed  evidence  of 
having  recently  borne  young.  Probably  in  the  mountains  most 
young  are  born  early  in  May;  at  Nyack,  Mont.,  however,  a  female 
was  captured  on  June  24,  1895,  carrying  3  embryos.  The  young  are 
able  to  leave  the  nest  in  about  4  weeks  after  birth.  At  Pullman, 
young  were  first  observed  out  of  their  dens  between  May  4  and  10. 

Food  habits. — The  food  of  the  Columbian  ground  squirrel  com- 
prises a  great  variety  of  vegetable  substances  and  a  small  proportion 
of  animal  matter.  A  large  part  of  the  vegetable  food  consists  of  wild 
and  cultivated  grasses,  herbs,  and  fruits,  including  the  bulbs  of 
camas,  wild  onion,  and  glacierlily  {Erythronium  grandifiorum) ; 
stems,  leaves,  and  flowers  of  false-hellebore  (Veratrum),  buttercups, 
roses,  dandelions,  mule-ears  (Wyethia) ,  balsamroot  (Balsamorhisa) , 
camas  {Quamasia  quamash).^  lupine,  and  wild  lettuce;  currants, 
gooseberries,  strawberries,  and  serviceberries  (Amelanchier) . 

On  cultivated  lands  the  squirrels  consume  the  stems  and  heads  of 
clover,  alfalfa,  bluegrass,  oats,  rye,  wheat,  and  barley ;  vines  of  pota- 
toes, beans,  and  peas ;  lettuce,  carrots,  and  probably  other  vegetables. 

Grasshoppers,  cicadas,  and  caterpillars  are  frequently  eaten,  and 
sometimes  fish,  if  the  habitat  borders  a  lake. 

Economic  status. — Wherever  it  comes  in  contact  with  agriculture 
the  large  Columbian  ground  squirrel  is  destructive,  particularly  to 


-j^g  NORTH  AMERICAN  FAUNA  [No.  56 

grain,  clover,  and  pasture.  When  uncontrolled,  the  animals  become 
numerous  and  may  destroy  practically  entire  crops  in  the  area  where 
they  are  living.  Shaw  (1925g,  p.  264),  writing  of  the  section  around 
Pullman,  Wash.,  says: 

During  7  successive  years,  7,000  squirrels  were  trapped  on  416  acres  of  the 
college  farm,  or  2.4  squirrels  per  acre  each  year.  A  successful  wheat  raiser 
near  Steptoe,  V/ash.,  trapped  1,200  squirrels  on  200  acres  in  1  year,  or  6 
squirrels  per  acre. 

Shaw's  experiments  showed  that  single  animals  kept  in  confine- 
ment under  natural  conditions  in  the  course  of  a  season  destroyed, 
on  an  average,  50l^  pounds  of  winter  wheat. 

This  species  has  been  shown  to  be  in  large  part  responsible  for  the 
dissemination  of  Rocky  Mountain  spotted  fever,  Birdseye  (1912,  p. 
10),  reporting  on  his  studies  in  the  Bitterroot  Valley,  Mont.,  says 
that  it  is  undoubtedly  the  most  important  host  of  the  two  younger 
stages  of  the  fever  tick,  and  is  almost  always  infested  with  ticks 
Avhen  occurring  in  suitable  country.  Plague  infection  was  demon- 
strated in  specimens  of  this  species  taken  in  Wallowa  County,  Oreg., 
in  1935  (Meyer,  1936,  p.  964). 

PARRY'S  GROUND  SQUIRREL  AND  RELATED  RACES 

General  habits. — Richardson  (1825,  p.  319),  writing  of  Parry's 
ground  squirrel  {Gitellus  parryii  'paiTyii)  as  observed  on  the  Arctic 
coast  between  the  mouth  of  the  Mackenzie  and  Bathurst  Inlet,  says : 

The  gray  Arctic  marmot  is  common  in  stony  barren  tracks,  but  delights  chiefly 
in  sandy  hillocks,  amongst  rocks,  where  it  burrows,  living  in  society. 

Anderson  (in  Stef ansson,  1913,  p.  510) ,  writing  also  of  the  Arctic 
coast  in  the  same  region,  says  that  these  squirrels  Avere  found  at 
many  points  along  the  coast  in  sandy  clay  hills  and  were  particularly 
abundant  in  sandy  alluvial  river  bottoms.  Along  the  Mackenzie 
River,  below  Fort  Good  Hope,  E.  A.  Preble  found  the  animals  liv- 
ing in  burrows  in  the  clay  banks,  well  above  high- water  mark.  On 
the  Barren  Grounds  near  Cape  Eskimo,  Hudson  Bay,  he  found  them 
occupying  gravellj^  ridges,  either  old  shore  lines,  or  deposits  left  in 
the  process  of  glaciation,  and  around  Artillery,  Clinton-Colden,  and 
Aylmer  Lakes,  Seton  and  Preble  (Seton,  1911,  p.  342)  found  them 
frequenting  similar  situations. 

In  McKinley  Park,  Alaska,  O.  J.  Murie  reported  the  subspecies 
G.  'p.  plesius  numerous  in  the  valleys,  on  the  slopes,  and  on  the  ridges. 
Some  had  dug  their  burrows  among  willows  and  in  vegetation  on  the 
slopes,  and  others  lived  among  rocks.  A  burrow  dug  out  there  was 
found  to  have  two  entrances  and  many  ramifications;  its  greatest 
depth  was  27  inches.  In  the  Delta  River  region  he  found  the  squir- 
rels inhabiting  the  river  bars  and  the  flats  among  the  dwarf  birches 
and  willows,  as  well  as  on  the  hills  where  cover  was  scarce.  In 
northern  British  Columbia,  Preble  found  them  in  broad  nearly  level 
valleys  clothed  with  shrubby  vegetation,  or  on  the  gentle  lower  slopes 
of  mountains,  and  seldom  or  never  above  timber  line. 

Richardson  speaks  of  the  alarm  note  of  this  species  as  "a  kind  of 
a  whistle",  and  when  the  animal  is  in  terror  this  note  is  said  to  re- 
semble the  sound  of  a  watchman's  rattle. 

HibernaMon. — R.  M.  Anderson  (in  Stefansson,  1913,  p.  510)  states 
that  on  the  Arctic  coast,  most  of  these  squirrels  go  into  hibernation 


19381  REVISION  OF  THE  GROUND  SQUIRRELS  17 

the  latter  part  of  September,  though  a  few  remain  out  until  the 
middle  of  October ;  and  that  they  reappear  in  spring  about  the  middle 
of  April.  At  Collinson  Point,  however,  on  October  2,  they  were  out 
in  some  numbers,  and  at  Point  Barrow  individuals  have  been  taken 
on  October  15,  November  10,  and  December  3.  At  Wiseman,  on  the 
south  slope  of  the  Endicott  Range,  two  ground  squirrels  were  seen 
by  O.  J.  Murie  on  October  23  (1924). 

At  Cold  Bay,  the  Alaska  Peninsula  race  {G.  p.  ablusus)  was  active 
in  some  numbers  as  late  as  October  18  (1902)  (Osgood,  1904,  p.  32), 
and  at  Togiak,  Alaska,  a  specimen  was  collected  on  March  10  (1897). 
At  Chignik,  Alaska,  during  the  mild  winter  of  1911-12,  the  squirrels 
were  seen  occasionally  throughout  the  winter  and  a  specimen  was 
captured  on  February  13.  The  small  mountain  form  {G.  p.  plesius) 
was  observed  at  Teslin  Lake,  Yukon,  on  October  3  and  specimens 
were  taken  in  the  Tanana  Hills,  Alaska,  on  March  4. 

Breeding. — Richardson  (1825,  p.  318)  records  taking  a  female  that 
contained  seven  embryos  at  Pomt  Lake,  Mackenzie,  on  June  13. 
Judging  from  the  size  of  two  young  individuals  taken  at  Old  Fort 
Good  Hope,  Mackenzie,  it  seems  probable  they  were  born  about  the 
middle  of  May.  Echnund  Pleller  recorded  a  female  of  G.  p.  plesius 
suckling  young  on  June  10,  and  another  carrying  a  single  large 
embryo  on  June  11,  at  Telegraph  Creek,  British  Columbia. 

Food  habits. — Richardson  (1825,  p.  319)  reported  the  food  of 
Parry's  ground  squirrels  to  be  entirely  of  vegetable  origin.    He  says : 

In  upwards  of  50  individuals  examined  at  various  periods,  no  animal  sub- 
stance was  detected  in  the  pouches  or  stomachs.  At  Point  Lake  in  lat.  65°, 
their  pouches  were  observed  about  the  middle  of  June  to  be  filled  with  the 
berries  of  the  Arbutus  alphia  and  Vaccinium  vttis-idaea,  which  were  just  then 
laid  bare  by  the  melting  of  the  snowy  covering,  under  which  they  had  Iain  all 
winter.  In  the  end  of  July,  on  the  shores  of  the  Arctic  Sea,  their  pouches 
contained  the  seeds  of  a  Polygonum,  and  in  Five  Hawser  Bay  in  September, 
they  were  filled  with  the  seeds  of  astragali. 

At  Aylmer  Lake,  Seton  (1911,  p.  237)  obtained  a  ground  squirrel 
with  its  cheek  pouches  full  of  mushrooms. 

Anderson  (in  Stefansson,  1913,  p.  510)  states  that  along  the  Arctic 
coast,  the  squirrels  fed  mainly  on  the  roots  of  various  species  of 
Polygonum. 

The  stomach  of  a  specimen  of  G.  p.  ablusus,  taken  on  Unimak  Island, 
Alaska,  May  8,  1925,  and  examined  in  the  Biological  Survey,  con- 
tained the  following  materials:  21  caterpillars  and  lepidopterous 
pupae,  60  percent;  1  tipulid  larva  and  5  Bibio  larvae,  4  percent;  2 
beetles  {Gryobius  sp.)  ;  1  ichneumonid  and  a  spider,  trace;  2  berries 
{Vaccinium  sp.),  2  percent;  a  few  leaves  of  Empetrum  nigrum  and 
other  vegetable  matter,  34  percent. 

YUKON  VALLEY  GROUND  SQUIRREL 

General  habits. — Osgood  (1900,  p.  31)  describes  the  habits  of  the 
Yukon  Valley  ground  squirrel  {Gitellus  osgoodi)  as  follows: 

From  Fort  Selkirk,  near  the  limit  of  Spermophilus  plesius  in  the  interior, 
nearly  to  Circle,  we  saw  no  signs  of  ground  squirrels  of  any  kind.  Just  before 
reaching  Circle,  however,  we  began  to  see  unmistakable  signs  of  them  and  were 
soon  attracted  to  a  small  colony  by  their  clicking  calls  which  reached  our  eai-s 
as  we  floated  down  in  midstream.  The  call  is  executed  in  about  the  same  time 
as  that  of  8.  plesius,  but  its  pitch  is  much  lower  and  its  effect  on  the  ear  is 
154970—38 2 


Ig  NORTH  AMERICAN  FAUNA  [No.  56 

utterly  different.  It  suggests  the  click  of  castanets.  On  going  ashore  we  found 
their  burrows  and  connecting  paths  scattered  over  quite  an  area  on  the  hillside. 
The  colony  occupied  the  open  hillside  and  a  few  ledges  of  loose  rock,  and  even 
extended  down  into  a  thicket  of  alder  and  willow  at  the  foot  of  the  hill.  The 
animals  were  very  shy  and  became  much  excited  at  our  approach.  Their 
long  tails  were  very  noticeable  in  marked  contrast  to  the  short  ones  of  8. 
vlesius,  which  we  had  been  accustomed  to  seeing. 

Writing  of  his  second  trip  down  the  Yukon,  Osgood  (1909,  p.  22) 
writes  of  these  ground  squirrels  as  follows : 

Many  of  their  burrows  are  made  in  the  sandy  banks  of  the  river,  often  only 
3  or  4  feet  above  high-water  mark,  and  usually  open  under  the  overhanging 
turfs  of  the  bank  or  among  the  exposed  roots  of  trees  and  shrubs.  Higher  up 
they  are  variously  situated  on  the  hillsides,  where  the  little  boreal  sagebrush 
{Artemisia  frigida)  flourishes.  As  a  rule,  however,  the  hillside  burrows  are 
not  in  exposed  places,  but  are  more  or  less  sheltered  by  small  bushes  near 
the  edge  of  the  timber.  The  animals  were  rather  quiet  and  seldom  gave  their 
clicking  cry  except  when  alarmed.  They  fought  viciously  when  being  taken 
from  traps,  often  lunging  at  vis  with  mouth  open  and  claws  spread.  Several 
were  seen  at  the  water's  edge,  and  tracks  were  abundant  on  the  damp  sand, 
but  whether  or  not  they  drink  there  was  not  ascertained.  Nearly  all  the 
females  taken  had  the  mammae  distended  with  milk.  Apparently  most  of  the 
young  were  too  small  to  leave  the  burrows.  At  one  place  5  little  squirrels  all 
of  a  size  and  evidently  from  the  same  mother  were  caught  in  rapid  succession. 
Of  these,  4  were  normal  in  color  and  the  fifth  was  in  the  black  phase.  Among 
adults  the  black  phase  was  found  in  about  the  same  proportion. 

STRIPED  GROUND  SQUIRRELS 

General  habits. — The  striped  ground  squirrels  {Gitellus  tridecem- 
lineatus  subspp.)  dwell  chiefly  on  dry  grassy  prairies  and  to  a  less 
extent  in  sandy  river  bottoms  and  the  brushy  borders  of  tmiber 
tracts.  They  are  gregarious  only  to  a  slight  extent,  and  not  at  all 
sociable,  individuals  usually  living  a  more  or  less  solitary  life  and 
often  digging  a  number  of  burrows,  some  of  which  are  shallow  and 
are  used  for  temporary  shelter  and  others  of  more  elaborate  con- 
struction for  more  permanent  use.  These  latter  are  ordinarily  in 
the  hard  soil  of  upland  pastures  or  meadows  and  are  said  always  to 
have  two  entrances.  They  descend  steeply  for  a  short  distance, 
then  extend  horizontally.  They  may  be  as  much  as  20  feet  in  length 
and  from  4  to  46  inches  in  depth.  Usually  there  is  no  earth  piled 
around  the  entrance,  the  rim  of  the  burrow  being  level  with  the 
surface  and  thus  quite  inconspicuous.  Frequently  the  burrows  are 
plugged  with  earth  by  the  squirrels  after  entering,  especially  during 
hibernation.  Sometimes  abandoned  burrows  of  other  rodents  are 
used,  including  those  of  prairie  dogs,  kangaroo  rats,  and  pocket 
gophers. 

Nests  of  dry  grass  of  a  spherical  shape  are  found  usually  in  the 
longer  permanent  burrows,  at  depths  varying  from  3  to  29  inches 
(Johnson,  G.  E.,  1917,  p.  264).  The  nests  are  used  in  spring  to  house 
the  young,  in  summer  for  storage  of  food  supplies,  and  in  winter 
for  hibernating  quarters. 

Breeding  activities  are  at  their  height  during  April,  and  the 
young,  numbering  from  5  to  13  (commonly  6  to  10),  are  brought 
forth  ordinarily  in  May  or  early  in  June.  The  gestation  period  is 
given  by  Wade  (1927,  p.  271)  as  between  27  and  28  days. 

The  note  of  this  species  is  described  by  Bailey  as  "a  rapid  bird- 
like trill  or  trembling  whistle — a  long  drawn-out  chur-r-r-r-r  in  a 
high  key." 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  19 

Hibernation. — The  date  of  entering  on  the  winter  sleep  varies  with 
season  and  locality.     At  Lincoln,  Nebr.,  Wade   (1930,  p.  169)   re- 

gorted  that  in  1927  nearly  all  had  disappeared  by  the  first  week  of 
eptember,  while  in  1926  they  remained  out  much  later,  small  ninn- 
bers  being  seen  until  October  17,  when  the  last  one  was  noted.  In 
Colorado,  according  to  Burnett  (1914,  p.  6),  the  latest  date  recorded 
is  November  9,  and  the  earliest  date  in  spring,  March  23.  Other 
late  fall  dates  are:  October  30  (Illinois),  November  3  (Springer- 
ville,  Ariz.),  and  November  23   (Oklahoma). 

Wade  (1927,  p.  270)  states  that  in  the  vicinity  of  Lincoln,  Nebr., 
these  squirrels  emerge  from  hibernation  between  the  middle  of 
March  and  the  first  of  April;  in  1926  the  first  were  seen  on  March 
17.  Near  Minneapolis,  Minn.,  they  were  reported  to  appear  1  year 
on  March  17  and  2  years  on  April  5.  In  southern  Manitoba,  accord- 
ing to  Seton,  they  may  come  out  as  early  as  March  27,  or  in  back- 
ward seasons  as  late  as  April  20.  Johnson  (Johnson,  Foster,  and 
Coco,  1933,  p.  266)  states  that  in  west-central  Kansas  the  males 
appear  in  numbers  above  ground  usually  about  the  middle  of  March 
and  the  females  about  the  last  of  March  or  first  of  April. 

Food  habits. — The  striped  ground  squirrels  feed  on  a  variety  of 
wild  plants  and  seeds,  in  addition  to  cultivated  grains,  and  are 
especially  fond  of  grasshoppers  and  other  insects.  Bailey  (1893,  p. 
39)  has  given  an  extended  account  of  the  food  of  this  species,  in 
which  he  shows  that  more  than  half  the  contents  of  80  stomachs 
examined  consisted  of  insects,  including  grasshoppers,  crickets, 
caterpillars,  beetles,  ants,  and  insects'  eggs.  The  A^egetable  matter 
comprised  oats,  wheat,  cactus  fruit,  nightshade  berries,  roots,  herb- 
age, and  seeds  of  goosefoot  {Ghenopodium).,  knotweed  {Polygo- 
num)^ and  sunflower  {Helianthus).  Eleven  cheek  pouches  of  this 
species  examined  contained  only  seeds,  including  wheat,  oats,  millet, 
deervetch  {Lotus),  and  seeds  of  porcupine  grass  {Stipa  spartea), 
sunflower,  gromwell  {Lithospermum) ,  bristlegrass  {Setaria),  Pani- 
cum,  ragweed  {Ambrosia),  and  black  locust  {Robinia).  To  the  list 
may  be  added  cotton,  clover,  and  flax  seed,  wild  beans,  and  seeds  of 
dandelion,  vetch,  ricegrass  (Oryzopsis),  gum  weed  {Grindelia),  and 
the  buffalo-bur  {Solarium  rostratum).  Morris  M.  Green  (1925,  p. 
176)  records  the  capture  of  a  striped  ground  squirrel  that  had  its 
cheek  pouches  bulging  with  196  large  seed  pods  of  the  sleepy  catchfly 
{Silene  antirrhina). 

Much  of  the  dry  food  gathered  by  these  squirrels  is  stored  in 
their  burrows;  concerning  this  habit,  Kennicott  (1857,  p.  77)  writes: 

Many  of  our  farmers  suppose  that  this  animal  feeds,  in  winter,  upon  stores 
of  provisions  laid  up  in  its  hole  for  that  season;  for,  though  it  spends  the 
winter  in  a  state  of  profound  torpor,  it  collects  food  in  its  hurrow.  This  is 
done  in  spring  and  summer,  as  well  as  in  autumn.  Considerable  stores  of 
grain,  seeds,  roots,  &c.,  are  found  thus  collected,  in  large  sidechambers  exca- 
vated for  their  reception  in  the  burrow.  Corn,  wheat,  and  oats  are  stored 
up,  when  taken  from  the  newly-planted  fields  in  spring,  with  buckwheat  and 
winter  wheat  later  in  the  season,  as  well  as  heads  of  grain  taken  from  the 
edges  of  the  fields  in  harvest  time.  I  have  seen  more  than  a  quart  of  crab- 
apples  taken  from  the  burrow  of  one  which  had  carried  them  several  rods 
from  a  tree.  George  and  Frank  Kennicott  inform  me  that  they  observed  one, 
the  burrow  of  which  was  near  a  lone  burr-oak,  on  the  prairie,  to  carry  great 
quantities  of  acorns  into  his  hole ;  and  another  was  killed  by  them,  the  cheek- 
pouches  of  which  were  crammed  with  the  dry  ovaries  of  a  prairie  plant,  the 
seeds  of  which  were  exceedingl.v  minute.     From  this,  it  would  appear  that  the 


20  NORTH  AMERICAN  FAUNA  [No.  56 

striped  spermophile  at  all  seasons  carries  portable  articles  of  food  to  its  bur- 
row to  be  eaten.  He  certainly  takes  no  food  from  the  time  lie  first  becomes 
torpid,  in  autumn,  until  be  again  becomes  active  late  in  the  following  spring. 

Johnson  records  a  burrow  of  this  species  in  which  the  nest  cavity 
was  entirely  filled  with  imshelled  oat  kernels,  estimated  to  number 
about  23,000,  and  another  burrow  that  contained- 2,000  or  3,000  wheat 
kernels. 

This  species  shows  a  rather  decided  taste  for  flesh  food,  and  it  has 
several  times  been  reported  to  capture  and  kill  mice  (Bailey,  V.,  1893, 
p.  38),  and  small  chickens  (Bailey,  B.,  1923,  p.  129;  Green,  1925,  p. 
175),  and  even  to  feed  on  the  bodies  of  its  own  kind. 

Econotnic  status. — The  most  serious  charge  against  these  ground 
squirrels  is  that  they  dig  up  and  destroy  newly  planted  corn.  Wliere 
the  squirrels  are  abundant,  this  habit  may  result  in  serious  damage 
to  a  crop  but  ordinarily  the  depredations  are  confined  to  a  few  row,s 
on  the  edge  of  a  field.  Peas,  beans,  cucumbers,  squashes,  beets,  straw- 
berries, and  other  garden  crops  are  sometimes  damaged,  and  fields 
of  wheat  or  oats  are  occasionally  drawn  upon  for  supplies  to  be 
stored  in  the  burrows. 

Against  these  destructive  tendencies  must  be  placed  the  evident 
fondness  of  the  squirrels  for  grasshoppers,  cutworms,  webworms,  and 
other  injurious  insects,  the  destruction  of  which  undoubtedly  exercises 
an  important  check  on  the  ravages  of  the  pests.  Wherever  the  squir- 
rels occur  on  extensive  grasslands  they  are  distinctly  beneficial, 

MEXICAN  GROUND  SQUIRRELS 

General  ha'bits. — The  Mexican  ground  squirrels  {Citellus  mexi- 
canus  subspp.)  inhabit  sandy  plains  where  there  is  a  growth  of  cactus 
or  mesquite,  and  both  in  Mexico  and  the  United  States  they  range 
out  into  cultivated  fields  of  corn  or  other  grain.  Their  burrows, 
usually  situated  at  the  base  of  mesquite  or  other  bushes  or  on  the  edge 
of  a  bunch  of  cactus,  descend  nearly  perpendicularly  for  a  foot  or 
more,  then  slope  down  at  an  angle  still  deeper. 

Apparently  these  squirrels  do  not  hibernate,  but  they  have  the 
habit  of  plugging  the  entrance  to  their  burrows  after  going  in,  and 
during  cold  weather  they  may  remain  under  ground  for  considerable 
periods.  Th&y  are  shy  and  usually  silent,  but  Nelson  states  that  they 
have  a  shrill,  whistling  note  of  alarm. 

Food  ha'bits. — Bailey  (1931,  p.  115)  reports  this  species  feeding  in 
about  equal  proportions  on  seeds  and  insects.  Mesquite  beans  and 
seeds  of  Acacia  are  said  to  be  favorite  foods  and  doubtless  many 
other  seeds  are  eaten.  At  Langtry,  Tex.,  Gaut  found  the  squirrels 
feeding  on  the  purple  blossoms  of  a  groundcherry  {Physalis  lobata) . 
They  often  range  into  cultivated  fields  and  do  considerable  damage 
in  spring  by  digging  up  corn,  melons,  beans,  and  sweetpotatoes,  and 
later  by  eating  ripening  grain. 

SPOTTED  GROUND  SQUIRRELS 

General  ha'bits. — The  spotted  ground  squirrels  {Citellus  spilosoma 
subspp.)  (pi.  5)  seem  to  prefer  dry,  sandy  soil  for  their  habitation. 
They  live  in  drifted  sand  along  river  flats,  in  grassy  parks,  in  open 
pine  forests,  and  to  a  less  extent  on  rocky  mesas.     Their  burrows 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  21 

are  usually  under  a  bush,  in  a  weed  patch,  or  under  an  overhanging 
rock.  D.  E.  Lantz  dug  out  a  burrow  at  Hugo,  Colo.,  that  had  three 
entrances  and  was  about  12  feet  in  length,  though  nowhere  more 
than  18  inches  below  the  surface.  It  terminated  in  a  small,  rounded 
chamber  in  which  was  a  slight  nest  of  grass.  In  some  localities  the 
squirrels  often  appropriate  the  burrows  of  kangaroo  rats  or  other 
rodents.  Like  most  of  the  ground  squirrels,  they  are  strictly  diurnal, 
but  are  rarely  seen  abroad  during  the  heat  of  midday.  They  are 
shy  and  retiring  and  of  gentle  disposition,  and  when  captured  alive 
make  attractive  pets.  Vernon  Bailey  describes  their  call  note  as 
"one  long,  bubbling,  birdlike  whistle." 

These  little  squirrels  do  not  wander  far  from  their  burrows,  and 
in  running  their  movements  somewhat  resemble  those  of  a  lizard; 
the  body  is  more  or  less  flattened,  the  tail  is  held  close  to  the  ground, 
and  the  squirrel  proceeds  by  short  runs  with  frequent  stops. 

Hibernation. — Hibernation  in  this  species  is  apparently  not  com- 
plete, at  least  in  the  more  southern  parts  of  its  range,  but  during 
severe  winter  weather  the  animals  usually  remain  within  their  bur- 
rows. Specimens  have  been  taken  near  Tucson,  Ariz.,  from  January 
27  on  through  February  and  March;  at  El  Paso,  Tex.,  February  9, 
20,  and  21;  in  Lake  Valley,  N.  Mex.,  November  13;  at  Deming, 
N.  Mex.,  December  4  and  6;  and  at  Chihuahua,  Mexico,  December  25. 

Food  habits. — The  food  of  these  ground  squirrels  is  largely  green 
vegetation  and  seeds.  The  following  items  have  been  identified  in 
their  stomachs :  Cactus  pulp,  mesquite  beans,  seeds  of  saltbush  {Atri- 
plex)^  sandbur  {Cenchrus).,  sunflower,  gourd,  and  iris;  grasshoppers 
and  beetles.  Living  mostly  in  uninhabited  regions  these  squirrels 
are  of  little  economic  importance.  They  undoubtedly  consume  con- 
siderable grass  and  in  cultivated  areas  are  sometimes  troublesome  in 
digging  up  planted  seeds, 

PEROTE  GROUND  SQUIRREL 

General  habits. — Little  is  known  of  the  habits  of  the  Perote  ground 
squirrel  {Citellus  jyerotensis) .  Nelson  reported  that  it  lives  in  the 
plains,  about  the  borders  of  wheatfields  and  cornfields. 

FRANKLIN'S  GROUND  SQUIRREL 

General  habits. — Franklin's  ground  squirrel  {Citellus  frankUnii) 
(pi,  6)  or  the  "gray  gopher,"  as  it  is  frequently  called,  inhabits 
prairies,  bushy  pastures,  grainfields  and  hayfields,  open  groves  of 
timber,  and  partly  dry  marshes,  Kennicott  (1857,  p,  79),  writing 
of  its  habits  in  Illinois,  says : 

It  is  observed  to  inhabit  the  thickets  of  low  bushes,  and  the  edges  of  the 
timber,  more  than  the  other  [C.  tridecemlincahis],  but  does  not  occur  in  the 
woods.  It  is  fond  of  digging  long  burrows  in  the  banks  of  ditches,  and  several 
times  I  have  seen  it  living  in  steep  river  banks,  as  well  as  under  small  wooden 
culverts  in  roads.  It  is  not  so  shy  as  the  striped  spermophile,  and  takes  up 
its  residence  quite  near  dwellings. 

Wood  (1910,  p.  528),  writing  from  Illinois  half  a  century  later, 
says  of  these  squirrels : 

At  present  a  necessary  condition  for  their  habitation  seems  to  be  the  presence 
of  some  shelter,  such  as  may  he  furnished  by  tall  grass,  or  a  field  of  clover, 
alfalfa,  or  grain.     Others  have  noticed  that  when  the  crop  on  such  a  field  is  cut 


22  NORTH  AMERICAN  FAUNA  [No.  56 

the  gophers  leave,  at  least  for  a  while,  and  my  own  observations  coincide  with 
theirs,  though  I  have  known  the  gophers  to  return  to  the  same  spot  after  the 
second  crop  of  alfalfa  had  started.  They  avoid  closely  cropped  pastures, 
well-kept  cemeteries,  lawns,  and  similar  places  where  the  striped  gopher  is 
especially  abundant,  yet  ev^en  in  such  localities  I  have  found  them  congregated 
under  a  heap  of  compost.  In  fact  such  a  shelter  seems  to  have  special  attrac- 
tions for  them,  as  noted  by  Bailey.     ... 

The  species  is  decidedly  gregarious,  nearly  always  being  found  in  colonies. 
As  their  burrows  each  have  several  openings  and  these  are  conspicuously 
marked  by  the  dirt  thrown  out,  a  colony  becomes  a  great  nuisance  in  a  hay 
or  grain  field.  The  conspicuousness  of  these  burrows  and  of  the  animals 
themselves  has  aroused  the  animosity  of  the  farmers  and  hastened  the  de- 
struction of  the  gophers. 

Kennicott  (1857,  p.  80)  describes  their  notes  as  "a  remarkably 
clear  whistle  twitter,  more  musical  than  the  voice  of  any  other 
mammal  I  ever  listened  to,  and  as  clear  as  that  of  a  bird." 

HibemoMon. — Franklin's  ground  squirrel  has  been  known  to  store 
up  in  September  as  much  as  half  a  peck  of  oats  in  a  burrow  under 
a  shock.  The  animals,  however,  become  excessively  fat  in  fall  and 
all  retire  to  their  burrows  in  October,  where  they  remain  in  hiberna- 
tion imtil  April.  Bailey  (1893,  p.  52)  gives  dates  of  their  appear- 
ance at  Bathgate,  N.  Dak.,  as  April  3  (1889)  and  April  21  (1890). 
Kennicott  states  that  they  have  been  found  hibernating  under  piles 
of  rails  and  in  corn  shocks,  and  in  two  instances  in  a  hay  stack. 
Eemington  Kellogg  states  that  he  has  found  the  animals  torpid  in 
a  burrow  about  3  feet  underground. 

Breeding. — The  young,  5  to  10  in  a  litter,  are  born  in  May  or 
June;  by  the  last  of  July,  in  North  Dakota,  they  are  out  of  their 
burrows  foraging  for  food.  Adults  carrying  embryos  were  taken  at 
Elk  River,  Minn.,  on  May  7,  and  at  Carberry,  Manitoba,  on  June  15. 

Food  habits. — The  vegetable  food  of  this  ground  squirrel  comprises 
about  two-thirds  of  the  total  and  includes  clover,  timothy,  junegrass; 
leaves  of  plantain,  mustard,  and  probably  other  wild  plants ;  wheat, 
oats,  barley,  newly  planted  corn*  seeds  of  needlegrass  (Stipa),  cockle- 
burs,  and  basswood;  strawberries  and  nightshade  berries.  Animal 
matter,  found  in  29  stomachs  examined  in  the  Biological  Survey, 
consisted  of  beetles  and  their  larvae,  caterpillars,  grasshoppers, 
crickets,  ants,  eggs  of  insects,  and  feathers  of  a  small  bird  (Bailey, 
1893,  p.  55).  Individuals  of  this  species  have  been  known  to  kill 
and  eat  wild  mice  and  a  young  rabbit,  to  rob  a  meadowlark's  nest, 
to  kill  a  wood  pewee,  to  capture  small  chickens,  and  to  eat  hens 
eggs. 

Economic  status. — ^In  localities  where  these  squirrels  are  abundant, 
they  may  do  considerable  damage  to  crops  by  digging  up  newly 
planted  corn  and  in  the  fall  by  burrowing  under  corn  shocks.  They 
sometimes  invade  vegetable  gardens  and  destroy  peas  and  cabbage, 
and  in  grainfields  they  destroy  considerable  grain  in  the  vicinity  of 
their  burrows. 

ROCK  SQUIRRELS 

General  habits. — The  several  races  of  the  rock  squirrels  {Citellus 
variegatus  subspp.)  (pis.  7  and  8)  have  habits  similar  to  other  ground 
squirrels;  all  show  such  a  decided  preference  for  inhabiting  rocky 
canyons  and  rocky  mountain  sides  that  their  name  "rock  squirrel" 
seems  quite  appropriate.  In  central  Mexico,  the  typical  race  {G.  v. 
variegatus)  is  reported  by  Nelson  and  Goldman  to  live  on  rocky  hill- 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  23 

sides,  along  stone  walls  or  irrigation  ditches,  and  in  cactus  or  mescal 
hedges,  often  ranging  out  into  cultivated  fields.  Their  burrows  are 
dug  usually  under  a  large  boulder  or  sometimes  in  thickets.  Al- 
though typical  ground  squirrels,  they  climb  trees  readily  in  search 
of  food,  and  occasionally  make  their  homes  in  hollow  trees  as  high  as 
15  or  20  feet  from  the  ground  (Bailey,  1905,  p.  85).  They  often 
climb  to  the  tops  of  juniper  trees  to  gather  the  berries,  and  into 
mesquite  trees  to  eat  the  green  buds  or  the  beans. 

The  rock  squirrels  are  knov/n  to  store  food  extensively  for  use  in 
winter,  and  it  seems  probable  that  over  the  greater  part  of  their 
range  they  remain  more  or  less  active  throughout  the  year.  Wliether 
they  ever  actually  hibernate  is  not  known.  During  the  colder  parts 
of  the  year  they  are  seen  out  of  their  dens  only  on  mild,  sunny  days. 
Their  food  supplies,  consisting  chiefly  of  acorns,  walnuts,  and  the 
seeds  of  peaches,  plums,  and  apricots,  are  stored  in  earth  burrows, 
in  cavities  in  cliffs  or  under  boulders,  and  in  hollow  trees. 

The  voice  of  the  rock  squirrel  is  described  as  "a  loud,  shrill 
whistle — a  single  note  repeated  at  irregular  intervals"  (V.  Bailey, 
ms.). 

Food  habits. — The  food  of  the  rock  squirrels  comprises  a  long  list 
of  vegetable  materials  and  includes  also  grasshoppers,  crickets,  cater- 
pillars, and  other  insects.  Nuts,  including  acorns,  walnuts  {JuglaTis 
rupestris),  and  pine  nuts  {Pinus  edulis)  probably  furnish  a  large 
part  of  the  yearly  food.  Other  seeds  that  have  been  found  in  the 
cheek  pouches  or  stomachs  of  these  squirrels  are  tliose  of  mesquite, 
cactus,  saltbush  {Atriplex),  wild  gourd,  wild  cherries,  muskmelon, 
watermelon,  fragrant  sumac  {Rhus  aromatica)^  Nevada  jointfir 
(Ephedra nevadensis),servicebevry  {Amelanchier) ,  spurge  (Euphor- 
bia), and  marbleseed  (Onosmodium  oceidentale) ,  and  berries  of  the 
wax  currant  (Ribes  cereum).  The  rock  squirrels  are  reported  to 
feed  on  wild  figs,  cactus  fruit,  blossoms  of  the  mescalbean  (Sophora 
secundifora) ,  and  the  flowers  and  tender  tips  of  the  agave, 

A  specimen  of  Say's  rock  squirrel  (O.  v.  grammuims)  taken  in  New 
Mexico  had  its  pouches  stuffed  with  the  berries  of  the  cherrystone 
juniper  (Juniperus  monosperma)  ;  one  taken  in  Texas  had  filled  its 
pouches  with  the  berries  of  the  alligator  juniper  (Juniperus  pachy- 
phloea).  In  Colorado,  according  to  W.  L.  Burnett  (1918,  p.  23),  the 
food  of  rock  squirrels  of  this  subspecies  "consists  of  seeds  of  various 
kinds,  apples,  cherries,  apricots,  chokecherries,  blackberries,  squash, 
and  melons.  They  also  eat  garden  peas,  grains  of  all  kinds,  and  feed 
to  some  extent  on  the  seed  pods  of  the  Yucca  and  Indian  breadroot 
(Psoralea) ." 

Economic  status. — The  rock  squirrels,  wherever  they  come  in  con- 
tact with  agricultural  operations,  are  considered  a  serious  pest.  They 
are  known  to  carrj^  off  whole  ears  of  corn  and  to  damage  all  kinds 
of  grain.  Fruit  trees,  including  peaches,  pears,  plums,  and  apricots, 
are  visited  and  the  fruit  carried  off  to  be  eaten  or  the  seeds  stored. 

CALIFORNIA  GROUND  SQUIRREL  AND  RELATED  RACES 

General  habits. — Grinnell  and  Dixon  (1918,  p.  606)  describe  the 
habitat  of  the  California  ground  squirrel  (Gitellus  beecheyi  beecheyi) 
(pi.  8)  as  follows: 

Its  proforences  as  to  local  conditions  are  not  closely  limited,  except  that  it 
avoids  dense  chaparral  and  thick  woods.     It  frequents  pasture  lands,  grain 


24  NORTH  AMERICAN  FAUNA  [No.  56 

fields,  orchards,  sparsely  tree-covered  slopes,  small  mountain  meadows,  rock 
outcrops  on  the  tops  of  ridges,  and  even  granite  talus  slopes.  It  is  always 
most  abundant,  however,  in  the  open  situations,  and  its  decided  preferences  are 
such  that  it  thickly  populates  much  of  the  best  farming  and  grazing  lands  in 
the  State,  to  the  great  reduction  of  their  producing  value  from  the  human 
standpoint. 

Although  a  true  ground  squirrel,  this  species  is  able  to  climb  trees 
with  ease  and  the  animals  are  often  seen  in  oaks  or  other  nut-bearing 
trees  and  in  fruit  trees. 

Burrows  and  nests. — ^Writing  of  the  animals'  burrows,  Grinnell 
and  Dixon  (1918,  p.  606)  say: 

In  shallow  adobe  or  clayey  soil,  underlain  by  broken  rock,  the  burrows  were 
found  to  be  short,  of  small  diameter,  and  not  reaching  to  any  considerable 
depth.  Those  in  alluvial  or  sandy  soil  were  found  to  be  of  large  diameter, 
of  greater  extent,  and  to  reach  to  much  greater  depths. 

The  most  conspicvious  signs  of  activity  on  the  part  of  ground  squirrels  in 
any  locality  are  the  large  mounds  of  earth  that  have  accumulated  in  the  course 
of  excavating  the  burrows.  This  earth  is  commonly  thrown  out  in  a  fan- 
shaped  pile  directly  in  front  of.  and  to  the  sides  of  the  main  entrance  to  the 
burrow.  These  mounds  of  earth  are  often  3  or  4  feet  in  diameter  and  from  6 
to  10  inches  above  the  general  level. 

Seven  burrows  of  this  species  were  excavated  by  Grinnell  and 
Dixon,  who  report  that  the  shortest  occupied  burrow  was  5  feet  in 
length  and  the  longest  138  feet,  the  average  length  being  35.2  feet. 
These  burrows  varied  in  depth  from  18  to  66  inches  below  the  surf ace> 
Three  types  of  burrows  are  described  by  them  (1918,  p.  612)  : 

The  male  squirrels  were  usually  found  in  short,  shallow,  simple  burrows  at 
the  outskirts  of  the  "colony."  ...  It  is  believed  that  at  least  during  the 
breeding  season  the  male  squirrels  live  altogether  by  themselves  in  their  own 
individual  burrows. 

The  second  type  was  illustrated  by  a  single  burrow,  22  feet  in 
length  and  30  inches  deep,  containing  a  female  and  four  young  with 
eyes  still  unopened.  This  burrow  was  much  more  complicated  than 
those  occupied  by  the  males. 

The  third  type  of  burrow  might  well  be  called  a  "colonial  burrow",  as  it  is 
used  by  both  sexes  and  also  by  the  young  after  these  leave  the  nest  burrow 
and  begin  to  forage  for  themselves.  Colonial  burrows  are  used  largely  as 
"safety  zones."  They  afford  convenient  places  for  the  squirrels  to  duck  into 
when  danger  unexpectedly  appears.  These  burrows  are  often  from  100  to 
200  feet  in  length  and  form  a  communicating  system  of  underground  runways 
connecting  from  six  to  twenty  entrances  or  surface  openings.  .  .  . 

Each  burrow  occupied  by  a  single  squirrel  was  found  to  contain  at  least  one 
well-made  nest.  In  some  cases  there  were  two,  one  obviously  older  than  the 
other.  In  the  colonial  burrow  that  was  dug  out,  three  nests  were  found,  of 
which  two  were  new.  The  nests  were  always  placed  well  back  in  the  burrows, 
where  they  would  have  maximum  protection  from  digging  enemies  such  as 
coyotes  and  badgers.  The  cavities  in  which  the  nests  were  placed  were  short 
globular  chambers  and  were  usually  situated  slightly  above  and  to  one  side  of 
the  main  run,  so  that  the  drainage  was  away  from  rather  than  into  the 
nest.  .  .  . 

All  of  the  nests  found  were  of  similar  composition  and  construction.  Finely 
shredded  dry  grass  blades  and  roots,  and  fine  stems  of  foxtail  and  needlegrass, 
formed  the  bulk  of  the  constituent  material.  The  nests  were  spherical  in  shape 
and  deeply  cupped.  The  walls  were  from  two  to  two  and  one-half  inches  thick 
(1918,  p.  615). 

Breeding. — The  principal  breeding  season  in  the  lowlands  extends 
from  February  to  the  middle  of  April;  at  higher  altitudes  it  occurs 
later,  even  into  June.    The  litters  number  from  4  to  11,  averaging  7.5. 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  25 

In  the  lowlands  thq  majority  are  probably  born  the  last  of  March,  and  by 
the  last  of  April  the  first-born  are  beginning  to  appear  above  ground,  playing 
about  the  mouths  of  the  burrows  (1918,  p.  620). 

Hibernation. — In  these  ground  squirrels  hibernation  is  not  univer- 
sal, and  it  is  not  yet  known  to  what  extent  the  animals  become  dor- 
mant. Over  the  greater  part  of  their  range  some  individuals  may  be 
seen  abroad  most  of  the  year.  There  are  specimens  in  the  Biological 
Survey  collection  taken  at  Los  Banos,  Calif.,  on  January  3  and  4  and 
at  Modesto  on  December  13.  Grinnell  and  Dixon  (1918,  pp.  631,  632) 
present  a  table  showing  that  large  numbers  of  the  animals  were  taken 
in  January  in  Contra  Costa  County,  the  great  majority  of  which 
were  young  adults.  In  their  opinion:  "It  is  probable  that  the  full 
old-adult  population  is  not  abroad  aboveground  until  the  last  of 
February."  These  writers  cite  an/  instance  of  a  squirrel  observed 
closely  for  a  number  of  years  in  Pasadena  that  did  not  estivate  until 
its  second  year. 

Then  and  during  each  succeeding  year  of  its  life  it  estivated  regularly, 
becoming  very  fat  and  retiring  to  its  burrow  during  the  last  week  in  August. 
It  emerged  lean  and  hungry,  with  marked  regularity,  about  the  twenty-second 
of  each  following  February.  When  removed  from  the  burrow  at  intervals  dur- 
ing this  period,  the  squirrel  was  found  to  be  in  a  torpid  state,  with  respira- 
tion not  perceptible. 

It  seems  probable,  therefore,  in  view  of  this  single  instance,  that  a 
certain  proportion  of  adults  of  this  species  living  in  the  lowlands 
regularly  hibernate.  According  to  Grinnell  and  Storer  (1924,  p. 
164)— 

Those  individuals  which  live  above  the  snow  line  in  the  mountains  hibernate 
for  considerable  periods  during  the  winter  months.  In  Yosemite  Valley, 
ground  squirrels  in  1920  were  first  seen  out  of  their  burrows  about  the  middle 
of  March,  according  to  Mr.  Forest  S.  Townsley.  One  exceptional  individual 
was  seen  out  by  one  of  us,  on  the  Big  Oak  Flat  Road  below  Geutrys,  on 
December  28,   1914. 

Storage  of  food. — These  ground  squirrels  regularly  carry  off  in 
their  cheek  pouches  various  seeds  and  heads  of  grain,  as  well  as 
acorns  and  olives,  and  store  them  in  their  burrows.  Writing  of  this 
habit,  Grinnell  and  Dixon  (1918,  p.  628)-  say: 

In  Strawberry  Canyon  on  the  University  campus,  in  April,  the  squirrels  were 
harvesting  foxtail  and  alflleria  on  sunny  southern  exposures  where  the  plants 
had  matured  early.  Later  in  the  season,  during  late  June  and  eai'ly  July, 
these  same  squirrels  with  their  families  of  half-grown  young  were  found  to 
have  moved  down  the  hillsides,  some  150  yards,  to  the  moister,  shady  ground 
near  the  creek  bed  where  the  foxtail  was  still  green,  and  here  they  were  busily 
gathering  the  foxtail  heads  just  ripening  on  July  6.  .  .  . 

In  digging  out  a  colonial  burrow  near  Bakersfield,  Kern  County,  on  May  3, 
1918,  a  storehouse  was  uncovered.  This  consisted  of  a  cavity  or  pocket  off  the 
main  run,  which  measured  five  and  a  half  by  eight  inches  in  two  diameters 
and  was  eighteen  inches  beneath  the  surface  of  the  ground.  The  stored  food 
consisted  of  a  double  handful  of  nearly  dry  heads  of  foxtail  grass  carefully 
packed  in  dry  sand.  A  few  alfileria  seeds  were  also  included  with  the  foxtail 
(op.  cit.  p.  629). 

Merriam  (1910,  p.  5)  writes  of  the  storing  habit  as  follows: 

In  Modesto  in  May  1909,  Piper  found  stores  of  alfileria  seeds  packed  in  cavi- 
ties and  well  mixed  with  dry  sand.  In  December  of  the  same  year  he  ex- 
amined a  number  of  stores  of  grain  unearthed  by  a  farmer  while  scraping  and 
leveling  his  land.  Each  of  these  caches  consisted  of  from  a  pint  to  a  quart  of 
oats  stored  in  cavities  and  packed  in  dry  sand. 


26  NORTH  AlVIERICAN  FAUNA  [No.  56 

Hollister  was  told  by  farmers  at  Aptos  that  a  burrow  that  had 
been  opened  in  a  wheatfield  was  found  to  contain  3  pecks  of  shelled 
wheat. 

Food  habits. — The  California  ground  squirrel  feeds  on  a  great 
variety  of  seeds,  nuts,  fruits,  and  green  herbage.  Merriam  (1910,  p. 
4)  states — 

Acorns  are  a  favorite  food  and  where  obtainable  are  gathered  and  stored  in 
large  quantities.  The  same  is  true  of  nianroot  (Echinocystis  fahacea),  the 
seeds  of  which  are  eagerly  eaten,  according  to  Piper,  from  the  time  they 
begin  to  form  until  fully  ripe.  At  Modesto  the  squirrels  were  eating  them  as 
early  as  the  middle  of  May  and  as  late  as  the  middle  of  December.  Other 
favorite  seeds  are  those  of  elderberry  (Samiucus) ,  jimson  vs^eed  (Datura), 
wild  nightshade  (Solanum),  turkey  mullein  (Eremocarpus) ,  tarweed  (Madia), 
and  numerous  grasses.  Of  cultivated  nuts,  almonds  and  walnuts  are  preferred ; 
of  other  crops,  apples,  prunes,  peaches,  apricots,  figs,  olives,  certain  garden  vege- 
tables, the  seeds  of  cantaloupes,  watermelons,  and  citron  melons,  and  all  the 
grains  are  eaten  wherever  they  are  to  be  had,  and  green  alfalfa  and  clover  are 
sometimes  taken.  In  November — sometimes  earlier,  according  to  the  date  on 
which  the  early  rains  begin — tender  green  vegetation  becomes  abundant,  and 
the  ground  squirrels  turn  their  attention  to  it.  At  this  season  their  chief  food 
consists  of  green  stuff,  mainly  young  wild  oats  and  filaree,  the  latter  a  small 
member  of  the  geranium  family  widely  distributed  in  California  and  valued  as 
a  forage  plant.  In  several  localities  in  March  the  cheek  pouches  of  animals 
examined  by  Piper  were  filled  with  the  yet  green  seeds  of  filaree.  In  June  the 
pouches  are  often  filled  with  alfalfa  leaves  and  flowers.  In  southern  Cali- 
fijrnia  the  squirrels  are  fond  of  the  fruit  of  the  prickly  pear  (Opuntia). 

Grinnell  and  Dixon  (1918,  p,  628)  say  that  on  wild  land,  alfileria, 
foxtail,  and  bur-clover  are  perhaps  the  three  forage  plants  that  are 
eaten  to  a  greater  extent  than  any  others. 

The  same  authors  (p.  626)  mention  a  ground  squirrel  taken  at 
Cisco  in  October  that  was  carrying  in  its  pouches  92  seeds  of  the 
green  manzanita  (Arctostaphylos  patula)  and  another  taken  in  Mari- 
posa County  that  had  dug  up  and  was  carrying  in  its  pouches  12 
bulbs  of  a  species  of  wild-hyacinth  (Brodiaea  hyacinthina) . 

Economic  status. — It  may  be  seen  from  statements  in  the  life 
liistory  of  this  species  that  the  California  ground  squirrel  is  capable 
of  great  injury  to  agriculture.  In  California,  where  it  is  considered 
to  be  the  most  important  of  the  rodent  pests,  large  sums  of  money  are 
expended  in  efforts  to  control  its  depredations.  In  addition  to  the 
damage  inflicted  on  crops  of  grain,  forage,  fruits,  and  nuts,  the  ani- 
mals are  reported  to  destroy  young  chickens. 

In  recent  years  this  species  has  been  found  to  be  a  carrier  of  both 
bubonic  plague  and  tularemia.  Plague  appeared  in  California  in 
1900  and  shortly  thereafter  it  was  found  to  be  present  in  these  ground 
squirrels.  Dr.  W.  H.  Kellogg  (1935,  p.  856),  writing  of  the  plague 
in  California,  said : 

Infected  squirrels  [Citellus  beeclieyi]  were  found  in  1908,  and  plague  has 
been  enzootic  among  the  squirrels  of  California  ever  since.  At  that  time  an 
acute  and  very  severe  epizootic  ensued,  the  number  of  plague-infected  squirrels 
picked  up  in  that  county  [Contra  Costa]  being  over  1,700  during  the  few  years 
following  1908.  This  epizootic  extended  in  the  neighboring  counties  of  the  Bay 
area  and  it  was  accompanied  by  a  human  epidemic  in  San  Francisco  and  Oak- 
land, the  number  of  cases  between  May  1907  and  June  30,  1908,  when  the  last 
case  of  this  second  epidemic  of  human  plague  occurred,  being  160  and  the 
number  of  deaths  77. 

Eradicative  measures  were  carried  on  jointly  by  the  Public  Health 
Service  and  the  State  Health  Department  from  1908  to  1912,  covering 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  27 

most  of  California  and  parts  of  adjacent  States,  and  at  the  end  of 
that  campaign  it  was  thought  that  danger  of  further  spread  of  the 
plague  had  been  removed.  In  the  spring  of  1934,  however,  fresh  out- 
breaks of  plague  were  discovered  in  Kern  and  Tulare  Counties,  and 
as  a  result  of  exterminative  measures  carried  on  in  these  counties 
from  March  to  July,  5,973  squirrels  were  shot  and  2,853  found  dead, 
and  of  those  sent  to  the  laboratory,  118  were  reported  to  be  infected. 
The  number  of  plague  foci  located  was  41  over  an  area  of  approxi- 
mately 896  square  miles. 

Tularemia  was  discovered  in  the  California  ground  squirrel  by 
Surgeon  George  W.  McCoy  in  1910  (1911,  p.  53)  while  searching  for 
league  in  this  rodent.  According  to  Francis  (1937,  p.  106),  hovv- 
ever,  human  cases  of  tularemia  have  not  as  yet  been  traced  to  this 
animal. 

DOUGLAS'S  GROUND  SQUIRREL 

General  habits. — The  habits  of  Douglas's  ground  squirrel  {Citellus 
heecheyi  douglasii)  (pi.  8)  in  California  are  described  by  Grmnell 
and  Dixon  (1918,  p.  646)  as  follows: 

The  local  or  habitat  preference  of  this  species  is  more  exclusively  for  hilly 
country  than  in  the  case  of  the  California  ground  squirrel.  It  is  true  that  the 
Douglas  exists  out  on  the  floor  of  the  Sacramento  Valley  nearly  to  the  lands 
annually  flooded  along  the  river ;  but  it  occurs  there  interruptedly,  in  far  sepa- 
rated "colonies",  and  never  anywhere  are  the  great  numbers  reached  that  char- 
acterize heecheyi  in  the  San  Joaquin  Valley.  The  preferred  haunts  of  douglasii 
are  the  openings  or  glades  on  hillsides,  beneath  scattered  oaks  or  pines,  or  else 
the  open  tracts  along  stream  courses,  not,  however,  quite  down  to  the  water's 
edge.  The  edges  of  the  smaller  valleys  between  the  coast  ranges  are  well 
populated,  but  the  open  floors  of  these  valleys  are  not  often  invaded  very  far  or 
in  any  considerable  numbers.  Dense  chaparral  and  thick  woods  are  avoided 
altogether.  .  .  .  Steep  banks  seem  to  be  cho.seu  for  burrowing  into,  whenever 
available.  Many  burrows  open  under  rocks,  bushes,  and  tree  roots.  On  open, 
level  ground,  with  no  protective  shelter  at  hand,  the  mouths  of  the  burrows  are 
marked  by  good-sized  mounds,  showing  the  presence  of  an  extensive  system 
below  ground.  As  far  as  we  know,  no  one  has  yet  made  a  complete  excavation 
of  the  burrow  system  of  this  species. 

Douglas's  squirrel  is  reported  to  climb  trees  more  frequently  than 
the  other  members  of  the  heecheyi  group,  and  there  are  instances  of 
individuals  having  been  seen  as  high  as  30  to  60  feet  above  the 
ground. 

The  alarm  call  of  this  species,  according  to  Vernon  Bailey,  is — 

a  series  of  rasping  squeaks  with  a  rising  inflection,  somewhat  like  the  cry  of 
Ochotona.  It  is  neither  a  whistle  nor  a  chipper,  but  sounds  like  an  attempted 
bark  with  something  loose  in  the  animal's  throat. 

Merriam  mentions  an  individual  that  uttered  "a  shrill  whistle  of  sur- 
prising loudness  and  penetration,  suggesting  the  alarm  note  of  the 
marmots." 

Hibernation  apparently  is  more  prevalent  in  this  subspecies  than 
in  any  otlier  races  of  heecheyi;  at  high  altitudes  the  animals  are  re- 
ported to  disappear  completely  for  a  period  of  6  to  8  weeks  in  mid- 
winter. In  the  Sacramento  Valley,  at  Chico  and  St.  John,  however, 
they  were  found  out  of  their  burrows  on  sunny  days  in  winter  and 
6  specimens  were  taken  there  on  January  4  and  6,  1906. 

The  young  are  brought  forth  during  May  in  the  lowlands,  prob- 
ably later  in  the  mountains.  Two  specimens  taken  at  Lower  Lake, 
Calif.,  April  23,  contained,  respectively,  five  and  six  embryos;  one 


28  NORTH  AMERICAN  FAUNA  [No.  56 

taken  at  Slierwood,  Calif.,  May  5,  contained  seven  embryos ;  one  from 
Eel  River,  May  18,  contained  five;  and  one  from  Cliico,  May  20, 
contained  five,  nearly  ready  for  birth. 

Food  habits. — The  food  of  this  ground  squirrel  consists  largely  of 
the  seeds  and  fruits  of  a  variety  of  wild  plants,  with  the  addition  of 
cultivated  grain  and  some  insects  (grasshoppers).  The  plant  food 
recorded  by  the  field  collectors  of  the  Biological  Survey  as  found  in 
the  cheek  pouches  of  these  squirrels  is  as  follows:  Acorns,  chin- 
quapins, nuts  of  the  California  buckeye  {Aesculus  calif ornica)  and 
the  California-laurel  {Umhellularia  calif  ornica)^  maple  seeds,  berries 
of  skunkbush  {Rhus  trilohata),  camas  bulbs,  seeds  of  California  bur- 
clover  {Medicago  hispida),  alfileria,  and  bitterbrush  {Purshia  tri- 
dentata)^  wild  oats,  and  wheat.  Grinnell  and  Dixon  (1918,  p.  648) 
list  the  following  items  found  in  cheek  pouches  of  this  species;  29 
seeds  of  a  wild  lupine  {Lupinus  micranthus) ;  12  seeds  of  milkthistle 
{Silyhum  marianum) ;  219  grains  of  barley  and  one  head  of  buck- 
horn  plantain  {Plantago  lanceolata)  ;  121  seeds  of  bur-clover  {Medi- 
cago hispida) ;  181  seeds  of  California  brome  {Bromus  carinatus) 
and  a  piece  of  an  acorn;  29  seeds  of  Malta  star-thistle  {Gentaurea 
melitensis)  and  30  seeds  of  bur-clover;  14  whole  fruits  and  103  sepa- 
rate seeds  of  the  common  manzanita  {Arctostaphylos  inanzanita) . 

Economic  status. — Douglas's  squirrel  apparently  is  less  prolific  and 
never  reaches  the  extreme  abundance  of  the  subspecies  heecheyi  and 
flsheri.  Locally,  however,  the  animals  prove  destructive  to  crops  of 
wheat  and  barley  and  to  the  almond  crop ;  Grimiell  and  Dixon  (1918, 
p.  648)  state  that  the  squirrels  have  been  known  to  invade  apricot 
orchards,  where  they  climb  the  trees  and  take  out  the  apricot  pits, 
discarding  the  fruit  pulp. 

RING-TAILED  AND  GOLDMAN'S  GROUND  SQUIRRELS 

General  habits. — In  their  notes  on  Biological  Survey  field  work, 
Nelson  and  Goldman  write  of  the  habits  of  the  ring-tailed  and  Gold- 
man's ground  squirrels  {Citellus  annulatus  subspp.)  (pi.  9)  as 
observed  in  Colima,  Mexico,  as  follows : 

On  the  flat  country  about  Armeria  they  are  excessively  common  and  in  this 
locality  one  could  have  shot  20  in  a  morning.  As  a  rule  they  are  not  shy 
although  many  will  rush  into  their  burrows  at  first  glimpse  of  an  intruder.  We 
found  their  burrows  on  hillsides,  among  the  rocks ;  and  again  in  the  sandy 
flats,  along  walls  and  hedges  bordering  cultivated  fields;  they  are  equally  at 
home  in  the  silent  and  gloomy  shade  of  the  densest  groves  of  oil  palms,  with  a 
burrow  under  a  mass  of  fallen  palm  fronds  or  sheltered  by  the  thorny  growth 
of  mesquite  and  acacia.  Again  their  burrows  are  found  under  a  cactus  whose 
spreading  branches  give  safe  shelter  on  more  open  ground.  The  nuts  of  the 
oil  palm,  mesquite  beans,  cactus  seeds  and  the  fleshy  fronds  of  the  pear- 
leaved  cactus,  wild  figs,  moho  nuts,  and  a  variety  of  other  seeds  and  fruits 
make  up  their  varied  bill  of  fare.  In  going  silently  along  the  trails  leading 
through  the  dense  palm  groves  and  thickets  of  other  trees,  where  the  "tezmo" 
lives,  they  may  be  seen  gliding  silently  from  log  to  log  or  from  one  bunch  of 
brush  or  similar  shelter  to  another,  now  stopping  a  moment  to  dig  for  a  seed 
or  sitting  up  on  their  haunches  to  eat  some  morsel  and  then  on  again.  They  are 
often  seen  10  or  12  feet  up  on  the  trunk  of  a  small  tree — sometimes  out  on  the 
ends  of  branches  after  mesquite  beans,  cactus  leaves,  or  other  fruit — and  when 
surprised  they  frequently  run  up  a  tree  a  few  feet,  take  a  hasty  look  at  the 
intruder,  then  around  the  tree,  down  the  other  side  and  away  in  a  direct  line, 
so  that  before  one  knows  it  he  may  see  his  expected  prey  whisk  into  a  brush  pile 
or  hole  many  yards  away.  Often  they  will  crouch  close  to  the  ground  and  lie 
very  still  in  the  bushes  so  that  they  are  only  seen  by  accident,  whUe  others  will 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  29 

steal  softly  away  to  some  sheltering  hole  and  thence  utter  short,  shrill,  whis- 
tling or  chirping  notes  at  short  intervals.  This  is  the  only  note  we  have  heard 
them  give.  When  their  curiosity  is  aroused  they  will  draw  near,  stopping  to 
stand  up  on  their  hind  feet,  sometimes  stretching  the  body  up  so  that  the  tail 
is  used  to  help  support  the  body  as  on  a  tripod.  At  the  first  alarm  they  scurry 
away  into  the  first  shelter.  They  carry  their  tails  in  a  curve  quite  squirrel-like 
in  character  and  their  motions  are  more  light  and  agile  than  those  of  most 
spermophiles. 

LESSER  TROPICAL  GROUND  SQUIRREL 

General  habits. — The  habits  of  the  lesser  tropical  ground  squirrel 
{Citellus  adocetus)  are  described  in  the  field  notes  of  Nelson  and 
Goldman  as  follows: 

They  live  among  rocks  along  canyon  sides,  about  stone  walls  and  corrals 
near  ranches,  and  sometimes  their  burrows  are  located  in  open  ground  at  the 
base  of  a  tree  or  bush.  They  are  seen  running  about  at  all  hours  of  the  day, 
but  are  most  active  from  9  to  11  in  the  morning.  Near  ranch  houses  they 
become  quite  tame  and  often  approach  to  within  a  few  feet  of  the  doors  after 
scraps  of  food  thrown  out  by  the  people.  In  the  fields  and  scattered  woods 
where  they  occur  they  are  rather  shy  and  retreat  to  their  holes  at  the  first 
sight  of  a  person  or  other  cause  of  alarm. 

They  were  abundant  about  the  ranch  near  La  Huacana  rMichoacan]  and 
especiall.v  numerous  along  the  stone  walls  bordering  the  trail  near  the  ranch 
of  Agua  Blanca  and  in  the  old  lava  beds  extending  away  from  the  south  base 
of  the  volcano  of  Jorullo.  We  left  Agua  Blanca  early  in  the  morning  with 
the  sun  just  becoming  warm,  and  dozens  of  these  little  animals  were  seen 
scampering  along  the  trail  ahead  of  us,  sometimes  playfully  pursuing  one 
another  or  sitting  up  to  look  about.  As  we  drew  near  they  ran  to  the  stone 
walls  and  either  sat  on  the  top  or  took  refuge  in  the  crevices  and  with  heads 
projecting  from  the  holes  watched  us  pass.  Now  and  then  one  scurried  away 
to  a  hole  under  a  stone  or  at  the  foot  of  a  tree  or  bush.  Their  habits  here 
w^ere  remarkably  like  those  of  Citellus  annulatus  aloug  the  stone-walled  roads 
near  the  city  of  Colima.  The  present  species  has  a  sharp  chirping  call  note. 
At  the  ranch  near  La  Huacana  they  were  living  mainly  in  holes  under  rocks 
or  bushes,  but  some  also  in  stone  walls.  Wherever  they  are  located  along 
roads  they  have  become  accustomed  to  people  and  are  less  shy  than  in  more 
unfrequented  places. 

ANTELOPE  GROUND  SQUIRRELS 

General  habits. — The  antelope  ground  squirrels  (subgenus  Am- 
mospermophilus)  (pi.  10)  live  chiefly  in  Sonoran  Zone  deserts, 
occupying  open  country  among  bushes  and  clumps  of  cactus  and 
showing  a  preference  for  more  or  less  rocky  situations.  They  dig 
shallow  burrows  under  bushes  or  among  rocks  and  apparently  use 
also  the  burrows  of  other  animals,  especially  those  of  the  large  kan- 
garoo rats  {Dipodomys) .  They  apparently  do  not  hibernate,  but 
during  severe  weather  may  remain  for  long  periods  within  their 
burrows.  E.  R.  Sans  says  he  has  seen  them  out  on  top  of  a  foot  of 
snow.  They  are  active,  nervous,  and  very  wary  creatures,  and  when 
alarmed  run  rapidly  to  cover  with  their  tails  held  straight  up  or 
curled  over  their  backs.  They  are  good  climbers  and  are  often  seen 
sitting  in  a  bush  or  clump  of  cactus,  several  feet  alcove  the  ground. 
Their  notes  are  described  as  "a  shrill,  rapid  chipper."  The  youn^, 
numbering  usually  6  to  9,  or  occasionally  12,  are  brought  forth  in 
March  or  April. 

Food  habits. — The  food  of  the  antelope  squirrels  consists  chiefly 
of  the  seeds  or  berries  of  a  large  variety  of  desert  shrubs.  The 
fleshy  fruit  and  the  seeds  of  various  species  of  cactus  are  frequently 
eaten,  as  are  also  seeds  of  mesquite,  huisache   [Acacia  farnesiana), 


30  NORTH  AMERICAN  FAUNA  [No.  56 

yucca,  palo  verde  {Cercidium  fioriduin)^  ocotillo  {Fouquieria  splen- 
dens),  sotol  {Dasylirion  texanum),  saltbush  (Atriplex),  Kussian- 
thistle,  skunkbush  (Rhus  ti^ilohata) ,  greasewooa  {Sarcobatus)^  sun- 
flower, wild  plum,  and  single  leaf  pinyon  (Pinus  monophylla) . 
Small  numbers  of  insects  have  been  found  in  tlie  animals'  pouches. 

A  specimen  taken  at  Kesting  Springs,  Calif.,  February  9,  1891, 
had  46  grains  of  barley  in  its  cheek  pouches. 

Economic  status. — ^Living  chiefly  in  desert  regions,  the  antelope 
squirrels  do  not  often  come  in  contact  with  cultivated  crops;  but 
Bometimes  in  irrigated  valleys  they  are  attracted  to  grainfields  and 
gardens  and  in  such  cases  may  cause  damage  by  destroying  ripening 
grain  or  planted  seeds  of  melons  or  corn. 

MOHAVE  GROUND  SQUIRREL 

General  habits. — Burt  (1936,  p.  221)  has  given  an  account  of  the 
habits  of  the  Mohave  ground  squirrel  {Oitellus  mohavensis)  based 
on  a  study  made  at  Palmdale,  Calif.,  in  the  spring  of  1931.  From 
this  account,  the  following  facts  are  selected. 

The  animals  live  on  the  lower  desert,  preferring  areas  where  the 
soil  is  sandy  or  of  sand  mixed  with  gravel,  and  where  there  is  a 
sparse  growth  of  sagebrush.  Their  burrows  enter  the  ground  at 
an  angle  of  about  35° ;  one  examined  was  a  simple  tunnel  54  inches 
in  length,  12  inches  below  the  surface  at  its  deepest  point,  with  two 
entrance  holes  2  to  2i/2  inches  in  diameter.  Some  of  the  burrows 
had  been  partially  plugged  with  earth  after  the  entrance  of  the 
animal. 

The  squirrels  rarely  run  rapidly  for  any  distance,  and  when  danger 
threatens  they  dodge  into  a  hole  or  sometimes  crouch  low  on  their 
bellies  and  remain  quiet.  When  running  the  tail  is  carried  over  the 
back,  after  the  manner  of  Ammospermophllus,  but  is  not  twitched. 
If  slightly  startled  the  animals  rise  upon  their  hind  feet — "picket- 
pin"  fashion — with  the  front  legs  hanging  limply. 

A  squirrel  observed  for  50  minutes  on  April  12  fed  in  a  patch  of 
green  vegetation,  chiefly  alfileria;  occasionally  it  climbed  into  small 
bushes  to  a  height  of  about  a  foot  and  ate  some  green  buds. 

Its  call  "resembles  a  shrill  whistle.  It  is  a  high  pitched  peep, 
with  a  slight  rasping  effect." 

A  female  taken  March  29  contained  six  embryos ;  one  taken  April 
12  was  suckling  young. 

ROUND-TAILED  GROUND  SQUIRRELS 

General  habits. — The  round-tailed  ground  squirrels  [Oitellus  tere- 
tioaudus  subspp.)  are  typical  desert  animals,  living  in  the  hottest 
parts  of  the  Lower  Sonoran  Zone  in  southern  California  and  Ari- 
zona. They  occur  in  more  or  less  isolated  colonies  in  mellow,  sandy 
soil.  Grinnell  and  Dixon  (1918,  p.  669)  say  that  these  ground 
squirrels  prefer  areas  where  wind-drifted  sand  has  been  accumu- 
lated into  mounds  about  the  bases  of  mesquite,  creosote,  or  saltbushes. 
They  make  use  of  the  burrows  of  other  rodents,  particularly  kan- 
garoo rats,  but  sometimes  they  dig  burrows  for  themselves  in  the 
sandy  flats  or  in  the  banks  of  a  gulch  or  dike.  These  burrows  may 
be  5  or  6  feet  in  length  and  reach  a  depth  of  2  to  3  feet.  Several 
examined  by  Vernon  Bailey  contained  nests  of  grass  at  the  lower  end. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


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(\. 


^     1 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  31 

Living  in  a  mild  climate,  these  squirrels  apparently  do  not  hiber- 
nate completely,  but  they  are  rarely  seen  on  cold  or  cloudy  days  dur- 
ing the  winter  season  and  may  remain  in  their  burrows  for  somewhat 
extended  periods.  At  Fort  Lowell,  Ariz.,  in  midwinter,  A.  Brazier 
Howell  noted  them  out  only  about  once  a  week  until  January  24, 
after  which  they  became  abundant.  Early  in  February  the  females 
ventured  out  infrequently  and  appeared  ragged,  but  the  males  were 
in  good  pelage.  Near  Tucson,  Ariz.,  the  first  were  seen  out  of  their 
burrows  on  January  27.  A  specimen  was  taken  at  Needles,  Calif., 
December  12,  and  one  at  Agua  Caliente  on  January  15. 

Although  chiefly  ground  dwellers,  these  squirrels  occasionally 
climb  into  bushes  in  search  of  food  or  to  survey  the  surrounding 
country.  Swarth  (1929,  p.  349)  mentions  seeing  one  10  feet  or  more 
up  in  a  mesquite  tree.  Their  voice  is  described  by  Vernon  Bailey  as 
a  fine  shrill  whistle,  so  thin  and  sharp  that  it  sounds  like  the  note  of 
an  insect.  He  says  that  there  is  no  vibration  or  trill  to  it,  as  in  the 
voice  of  the  members  of  the  spilosoma  or  the  tridecemlineatus  groups, 
but  that  it  is  often  prolonged  and  evenly  sustained. 

The  young  are  brought  forth  in  March  and  April  and  there  may 
be  a  second  litter  later  in  the  season.  Two  specimens  taken  in  Death 
Valley,  Calif.,  April  7,  contained  six  and  seven  embryos,  respectively. 
Three  taken  at  Fort  Mohave,  Ariz.,  March  11  and  12,  contained  10, 
11,  and  12,  respectively.  One  taken  at  Ivanpah,  Calif.,  June  2,  con- 
tained eight. 

Food  habits. — Stephens  (1906,  p.  70)  says  of  this  species: 

The  food  is  seeds  the  greater  part  of  the  year;  these  are  stored  to  some 
extent.  In  the  spring,  during  the  few  weeks  when  green  vegetation  is  obtain- 
able, leaves  and  buds  are  eaten  voraciously. 

Grinnell  and  Dixon  (1918,  p.  671)  state  that  stems  of  the  "squaw- 
tea"  or  jointfir  {Ephedra)  and  leaves  of  the  mesquite  form  an  im- 
portant element  of  the  diet  wherever  and  whenever  obtainable.  They 
state,  also,  on  the  authority  of  W.  C.  Jacobsen,  that  in  the  Imperial 
Valley  these  squirrels  were  known  to  invade  alfalfa  fields  and  to  eat 
the  alfalfa  leaves,  discarding  the  stems. 

Among  the  food  elements  recorded  in  the  stomachs  or  cheek 
pouches  of  this  species  are  cactus  fruit,  blossoms  of  ocotillo  {Fou- 
quieria  splendens),  mesquite  beans  and  leaves,  seeds  of  plantain 
{Plantago)  and  of  goosefoot  {Chenopodium)  ^  wheat,  barley,  and 
small  insects. 

Living  mainly  in  desert  areas,  these  squirrels  rarely  come  in  con- 
tact with  agricultural  crops  and  they  are  therefore  of  little  economic 
importance. 

MANTLED  GROUND  SQUIRRELS 

General  habits. — The  mantled  ground  squirrels  (subgenus  Callo- 
f>permophilus)  (pi.  11)  inhabit  mountain  slopes  and  foothills,  living 
in  the  more  open  forested  country  among  rocks  and  fallen  timber. 
Their  burrows  are  dug  usually  under  rocks  or  stamps,  and  the  ani- 
mals spend  much  time  resting  quietly  on  some  rock  or  log  in  the  sun- 
shine. They  occasionally  climb  into  bushes  or  trees  to  a  height  of  20 
or  30  feet  m  search  of  food,  but  their  ordinary  habitat  is  on  the 
ground.  They  are  of  rather  sluggish  movements  and  when  running, 
elevate  the  tail  at  an  angle  of  about  45°.    Ordinarily  they  are  silent. 


32  NORTH  AMERICAN  FAUNA  [No.  56 

but  Bailey  says  that  on  occasions  tliey  utter  a  clear,  birdlike  whistle, 
very  shrill  and  piercing,  entirely  unlike  the  note  of  the  chipmunks. 
When  gathering  food  supplies,  they  often  pack  their  capacious 
cheek  pouches  so  full  that  their  cheeks  stand  out  as  in  a  case  of  the 
mumps.    In  fall  they  store  food  in  underground  chambers. 

Hibernation. — These  squirrels  become  very  fat  early  in  fall  and  by 
the  middle  of  September  most  of  them  have  retired  underground 
for  their  winter's  sleep;  a  few,  however,  may  be  found  out  of  their 
burrows  in  October  or  November  (Lake  Tahoe,  Calif.,  Oct.  6;  Tula- 
rosa  Mountains,  N.  Mex.,  Oct.  12 ;  Mogollon  Mountains,  N.  Mex.,  Oct. 
28;  Pikes  Peak,  Colo.,  Nov.  2  (Hatt,  1927,  p.  19) ).  In  the  Bitterroot 
Valley,  Mont.,  the  first  one  seen  in  spring  was  on  March  28  (1910) 
and  by  April  10  they  were  observed  in  numbers.  In  milder  climates 
they  may  come  out  of  hibernation  earlier  than  this.  Females  carry- 
ing four  to  six  or  rarely  eight  embryos  are  recorded  during  May, 
June,  and  July. 

Burrows  and  nests. — Hatt  (1927,  p.  8)  describes  a  burrow  examined 
in  Douglas  County,  Colo.,  as  follows : 

The  diametei'  of  the  burrow  at  the  entrance  was  3  inches.  For  the  distance 
of  a  foot  there  was  a  45°  angle  and  then  the  course  flattened  out  to  a  depth 
uniformly  8  inches  under  the  surface,  except  at  the  opposite  end  and  in  one 
of  the  pockets.  A  few  inches  past  the  entrance  the  tunnel  narrowed  down  to  a 
uniform  2-inch  bore.  At  one  place  in  its  course  the  roof  was  crossed  by  the 
root  of  an  aspen.  Farther  on  the  tunnel  passed  directly  under  the  base  of  a 
tree  and  beneath  its  roots. 

The  first  pocket  leading  from  the  main  passage  contained  no  debris  of  any 
sort,  and  at  the  time  of  the  excavation  could  not  have  been  in  use  unless  it 
was  a  passing  place  or  unlined  nesting  site. 

Six  feet  in  from  the  entrance  the  passage  forked,  one  lead  passing  directly 
to  the  nest,  the  other  passing  to  it  by  a  semicircular  arc.  A  runway  surrounded 
the  nest  on  three  sides,  from  which  there  were  four  passages  leading  in.  This 
nest  cavity  was  4  inches  deep,  the  nest  not  filling  the  space  available,  but 
occurring  more  as  a  mat  in  the  bottom  of  the  cup. 

A  passage  led  away  from  the  nest  in  the  direction  opposite  from  that  of  the 
other  main  passage.  Six  inches  from  the  cavity  this  forked,  one  branch  lead- 
ing from  an  empty  chamber  5%  inches  in  diameter,  beyond  which  was  a  blind 
lead  filled  for  a  distance  of  about  12  inches  with  old  nesting  material,  firmly 
packed.  The  other  branch  led  by  an  angular  path  and  a  sharp  grade  to  another 
entrance  completely  obscured  by  kinnikinnik  and  hidden  by  a  mat  of  leaves. 

Food  hatits. — The  food  of  the  mantled  ground  squirrels  is  chiefly 
of  vegetable  origin  and  comprises  a  large  variety  of  the  seeds  and 
berries  of  wild  plants,  including  acorns  and  seeds  of  yellow  pine 
and  Douglas  fir,  small  wild  beans,  serviceberries  (Amelanchier) , 
gooseberries  (Grossularm  irrigua),  currants,  thimbleberries,  and  the 
seeds  of  roses,  lupine,  puccoon  {Lithosipermum) .,  alfileria,  clover, 
Polygonum,  shepherds-purse  (Ca'pseUa) .,  milkvetch  {Astragalus) ., 
false-indigo  {Am.morpha  calif ornica) .,  willowweed  (Epilohium), 
beardtongue  {Penfsteinon),  bitterbrush  (Purshia  tridentata) .,  gilia, 
and  greengentian  (Frasera).  One  squirrel  captured  had  410  weed 
seeds  in  its  pouches :  another  had  taken  360  grains  of  barley,  gatliered 
along  a  road.  Mushrooms  are  frequently  eaten,  as  also  are  grass- 
hoppers, beetles,  caterpillars,  ants,  flies,  and  various  other  insects. 
Hatt  (1927,  p.  12)  reports  seeing  one  of  these  squirrels  feeding  on 
the  fruits  of  stickleaf  {Menfselia  nnuXtif,ora) .  Vernon  Bailey  ex- 
amined a  specimen  in  Oregon  that  had  filled  its  cheek  pouches  to 
their  limit  with  ripe  seeds  of  the  Nuttall  violet  {Viola  nuttallil). 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  33 

Economic  status. — ^Living  as  they  do  chiefly  in  mountainous  and 
unsettled  areas,  these  squirrels  rarely  come  in  contact  with  civiliza- 
tion. In  certain  valleys,  however,  they  at  times  forage  in  grain- 
fields  and  destroy  considerable  quantities  of  wheat,  oats,  or  barley. 
Around  hunters'  or  miners'  camps  they  are  often  attracted  by  stores 
of  food  and  unless  means  are  taken  to  keep  them  out  they  will  per- 
sistently carry  off  any  food  materials  that  appeal  to  their  taste. 


in4970 — 38- 


CLASSIFICATION  OF  THE  NORTH  AMERICAN  SCIURIDAE 

In  connection  with  the  present  revision  of  the  North  American 
ground  squirrels,  it  seemed  desirable  to  make  a  critical  study  of  all 
the  North  American  members  of  the  family  Sciuridae,  in  an  effort 
to  devise  a  classification  in  which  the  generic  and  subgeneric  groups 
can  be  based  on  the  most  constant  and  deep-seated  skeletal  charac- 
ters. This  has  proved  to  be  a  task  of  considerable  difficulty,  for 
although  the  various  groups  commonly  recognized  are  easily  sep- 
arable by  external  characters,  critical  study  of  their  cranial  and 
dental  characters  (pi.  12)  reveals  in  many  cases  close  relationship 
among  a  number  of  groups,  shown  by  extensive  gradation  from  one 
to  another  in  supposedly  diagnostic  characters.^ 

The  lack  of  agreement  among  zoologists  as  to  what  characters 
should  be  used  to  characterize  a  genus  results  in  great  diversity  of 
treatment  by  systematic  workers  and  consequent  confusion  of  the 
laymen,  who  are  naturally  less  interested  in  questions  of  relationship 
than  in  stability  of  the  names  they  are  called  upon  to  use. 

A  genus  is  sometimes  a  natural  group,  but  is  often  merely  a  concept 
in  the  mind  of  the  systematist  by  which  certain  related  species  are 
associated  under  a  single  generic  name.  The  limits  of  a  particular 
genus,  therefore,  may  be  subject  to  change  at  the  will  of  any 
reviser,  as  his  viewpoint  with  reference  to  generic  characters  changes, 
or  as  new  facts  or  new  species  come  to  his  attention.  This  situation 
is  well  illustrated  by  the  evolution  of  the  generic  concept  in  the 
mind  of  one  of  our  most  distinguished  American  zoologists,  the  late 
J.  A.  Allen.  In  his  monograph  of  the  Sciuridae,  published  in  1877, 
he  recognized  a  single  genus — Sciurus — for  all  the  tree  squirrels  of 
North  America  and  South  America.  The  five  outstanding  groups  of 
North  America  were  treated  as  species  (some  with  several  varieties) 
and  nine  additional  species  were  recognized  from  Middle  America 
and  South  America.  In  his  last  paper  on  the  squirrels,  published 
38  years  later  (1915),  working,  of  course,  with  a  vastly  increased 
quantity  of  material,  he  recognized  eight  genera  from  North  America 
and  nine  additional  genera  from  South  America.  Each  of  the  five 
North  American  species  recognized  in  1877  was  in  1915  given  full 
generic  rank — Tamiasciurus  for  the  red  squirrels;  NeosGiwrus  for 
the  eastern  gray  squirrel;  Otosciurus  for  Abert's  squirrel  of  the 
Southwest ;  H esperosciurus  for  the  western  gray  squirrel ;  and  Para- 
seiurus  for  the  fox  squirrels. 

The  same  tendency  to  give  generic  rank  to  practically  every  recog- 
nizable group  is  more  or  less  prevalent  today  among  workers  in 
other  branches  of  zoology.  Such  a  course  results  in  our  so-called 
genera  becoming  little  more  than  specific  groups.     The  purpose  of 

'  In  this  study  the  writer  has  had  the  advice  and  assistance  of  Gerrit  S.  Miller,  Jr., 
curator  of  mammals,  U.  S.  National  Museum,  who  generously  turned  over  a  partially  com- 
pleted key  to  the  genera  of  ground  squirrels  and  related  groups  and  also  checked  with  the 
author  the  cranial  characters  of  the  various  groups. 

34 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE    12 


UPPER    AND    LOWER    MOLARIFORM    TOOTH     ROWS   OF    CYNOMYS    LUDOVICI  ANUS. 

(Kiilarged  about  0  diameters.) 


pa  =  paracone. 
TOC  =  inetac()ne. 
pr  =  i)rotoc()iie. 


parf  =  paraconi(i. 
fn/  =  ent()coni<i. 
prii=  protocoiiiil. 


/i;/r/  =  hyp()Coni(l 
/)«.s  =  parastyle. 
;».■(  =  mesostyle. 


7K/«  =  ineta.style. 
/)r/  =  protolopli. 
;H7/-inetalopli. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE   13 


/ 


K  L 


a 


W 


BACULA  OF    VARIOUS  SCIURIDAE. 

(Enlarged  about  5}i  diameters — see  explanation  on  facing  page.) 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


35 


systematic  nomenclature  should  be  to  show  not  only  that  there  are 
diff ereTices  between  the  various  forms  but  also  that  there  are  resem- 
blances that  indicate  relationship.  Giving  a  generic  name  to  every 
recognizable  group  emphasizes  the  differences  between  related 
groups  but  fails  entirely  to  show  their  similarities. 

A  more  reasonable  and  satisfactory  classification  will  be  attained 
by  recognizing  as  subgenera  groups  that  are  distinguished  by  cranial 
characters  of  minor  importance,  or  that  show  gradation  in  cranial 
or  dental  characters  from  one  group  to  another.  This  treatment 
should  be  satisfactory  both  to  the  layman  and  to  the  systematist. 
One  who  is  interested  chiefly  in  having  a  definite  and  permanent 
name  to  use  for  every  species  may  disregard  the  subgeneric  name 
entirely,  while  the  technical  worker  who  desires  to  show  the  rela- 
tionship of  the  various  groups  can  do  so  by  the  use  of  both  generic 
and  subgeneric  names. 

Examination  of  the  baculum  (pi,  13),  or  penis  bone,  in  a  small 
number  of  individuals  representing  most  of  the  subgeneric  groups 
shows  that  this  bone  has  characters  that  are  of  assistance  in  defining 
the  groups.  The  writer  does  not  believe,  however,  that  in  the  ab- 
sence of  trenchant  cranial  characters,  the  morphology  of  the  baculum 
alone  should  be  considered  of  generic  value. 

The  North  American  Sciuridae  may  be  roughly  divided  into  four 
groups,  as  follows: 

1.  The  marmots  {Marmota)^  prairie  dogs  {Cynomys)^  and  ground 
squirrels  {Oitellus),  including  the  rock  squirrels  (Otospermopkilus) , 
mantled  ground  squirrels  {Callospermophilus)^  and  antelope  squir- 
rels (Ammospermophilus) ,  which  three  heretofore  have  been  treated 
by  some  writers  as  genera. 

2.  The  chipmunks  (Tamias  and  Eutamias) . 

3.  The  tree  squirrels  (Sciurus,  Tamiasciurus,  Microsciurus.  and 
Syntheosciu7-us) . 

4.  The  flying  squirrels  {Glaucomys). 


Explanation  of  Plate  13 
(Enlarged  about  3H  diameters) 


A.  Tamias  striatus. 

B.  Tamias  striatus. 
Eutamias  (Eutamias)  asiaticus. 
Eutamias    (Neotamias)    townsendii 

sonomae. 
Eutamias  (Neotamias)  quadrivitta- 

tus  frater. 
Eutamias  (Neotamias)  cinereicollis. 
Citellus     (Otospermophilus)     varie- 

gatus  grammurus. 
H.   Citellus  (Otospermophilus)  variega- 

tus  grammurus. 
Citellus  (Otospermophilus)  variega- 

tus  buckleyi. 
Citellus   (Cailospermophilus)   later- 
alis. 
Citellus   (Ammospermophilus)   har- 

risii. 


L.    Citellus   (Ammospermophilus)   har- 

risii. 
M.  Cynomys  (Cynomys)  ludovicianus. 
A^    Citellus    (Ictidomys)    tridecemline- 

atus. 
0.    Citellus  (Ictidomys)  mexicanus. 
P.    Citellus  (Poliocitellus)  franklinii. 
Q.    Citellus  (Citellus)  beldingi  oregonus. 
R.    Citellus  (Xerospermophilus)  tereti- 

caudus. 
S.    Sciurus  (Neosciurus)  carolinensis. 
T.    Sciurus  (Neosciurus)    variegatoides 

dorsalis. 
U.    Sciurus  (Parasciurus)   niger  limitis. 
V.    Sciurus  (Hesperosciurus)  griseus. 
W.  Sciurus  (Otosciurus)  aberti. 
X.    Glaucomys  volans. 


3g  NORTH  AMERICAN  FAUNA  [No.  56 

The  marmots,  prairie  dogs,  and  ground  squirrels  are  all  closely 
related.  In  comparison  with  the  tree  squirrels  they  are  character- 
ized in  general  by  a  shallower  brain  case;  narrower  interorbital 
region ;  more  wide-spreading  zygomata,  which  are  usually  not  paral- 
lel but  contracted  anteriorly  and  twisted  in  the  jugal  region  from  a 
vertical  toward  a  horizontal  plane;  the  upper  surface  of  the  jugal 
is  without  an  angular  process;  the  antorbital  foramen  is  broader 
(either  subtriangular  or  oval) ;  the  molars  are  usually  more  hypso- 
dont  and  the  crown  pattern  more  complicated;  and  the  anterior 
upper  premolar  (pm^)  is  always  present  and  often  of  relatively 
large  size.  This  tooth  is  of  varying  size  in  the  different  groups  of 
ground  squirrels  and  furnishes  a  character  useful  in  distinguishing 
the  subgenera. 

Key  to  Genera  and  Subgeneea 

a^.  No  antorbital  canal,  the  antorbital  foramen  piercing  the  zygo- 
matic plate  of  the  maxillary. 

6\  Premolars  f Genus  Tamias  (p.  46) 

1)\  Premolars  ^ Genus  Eutamias  (p.  47) 

c\  Antorbital  foramen  large,  suborbicular Subgenus  Eutamias  (p.  47) 

cl  Antorbital  foramen  smaller,  narrowly  oval-  Subgenus  Neotamias  (p.  47) 
o^  Antorbital  canal  present. 

6\  Anterior  lower  premolar  bearing  a  paraconulid Genus  Makmota  (p.  37) 

c\  Pollex  suppressed Subgenus  Mabmota  (p.  38) 

c^  Pollex  present Subgenus  Maemotops   (p.  38) 

6^  Anterior  lower  premolar  without  a  paraconulid. 

c\  Zygomata  not  parallel,  but  contracted  anteriorly,  and  an- 
terior    portion     twisted     toward     a     horizontal     plane 
(groimd  squirrels  and  prairie  dogs). 
d\  Upper  molar  rows  strongly  convergent 

posteriorly Genus  Cynomys  (p.  38) 

e\  Jugal  thickened  anteriorly Subgenus  Cynomys  (p.  38) 

e".  Jugal  not  thickened  anteriorly.  Subgenus  Leucocrossukomys  (p.  38) 
d^.  Upper  molar  rows  not  strongly  convergent 

posteriorly Genus  Citeulus  (p.  39) 

e\  Molars  relatively  hypsodont ;  parastyle  ridge  on  m^ 
and  m^  joining  protocone  with  an  abrupt  change  of 
direction. 

f.  Metaloph  on  pm*  continuous Subgenus  Citellus  (p.  40) 

f.  Metaloph  on  pm*  not  continuous Subgenus  Ictidomys  (p.  41) 

e".  Molars  relatively  brachydont;   parastyle  ridge  on  m^ 
and  m°  rising  evenly  to  join  the  protocone,  without 
abrupt  change  of  direction. 
f-.  Anterior    upper    premolar    simple ;    less    than    one- 
fourth  the  size  of  pm^. 
g^.  Upper  incisors  relatively  stout  and  distinctly  re- 
curved. 
li^.  Brain  case  rounded  on  upper  surface. 
t\  Supraorbital  foramen 

open Subgenus  Otospebmophilus   (p.  43) 

f.  Supraorbital  foramen 

closed Subgenus  Notociteixus  (p.  44) 

}f.  Brain  case  flattened  on  upper 

surface Subgenus  Ammospeemophilus  (p.  44) 

g^.  Upper   incisors    relatively    slender— not    distinctly 
recurved. 
7i-\  Postorbital  processes  long  and  slender;  rostrum 

longer Subgenus  Caixospermophixus  (p.  4.5) 

h^.  Postorbital  processes  short  and  stout;   rostrum 

shorter Subgenus  Xerospeemophilus  (p.  45) 

f.  Anterior  upper  premolar  more  than  one-fourth  the 
size  of  pm^,  showing  two  cusps  or  a  functional 
cutting  edge Subgenus  Poliociteixus  (p.  42) 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  37 

c^  Zygomata   nearly  parallel    (little  if  any  contracted  ante- 
riorly) and  nearly  vertical — not  twisted  (tree  squirrels). 
d\  Interorbital  region  relatively  narrow  and  deeply 

notched Genus  Glaucomys   (p.  52) 

d^.  Interorbital    region    relatively    broad    and    not    deeply 
notched. 
e^.  Upper  incisors  projecting  forward  (to  or  beyond  plane 
of  tip  of  nasals). 

f.  Upper  incisors  grooved Genus  Syntheoscixirus  (p.  52) 

f.  Upper  incisors  not  grooved Genus  Microsciueus  (p.  51) 

e■^  Upper  incisors  not  projecting  forward Genus  Sciukus  (p.  48) 

f.  Premolars  r- 

f/\  Notch   in   zygomatic  plate   of   maxillary   opposite 

m} Subgenus  Parasciurus  (p.  50) 

g^.  Notch    in   zygomatic   plate   of   maxillary   opposite 
pni*  (or  sometimes  the  division  between  pm*  and 

m^) Subgenus  Guerlinguetus  (p.  50) 

f.  Premolars  y. 

g^.  Notch   in  zygomatic   plate   of   maxillary   opposite 
pni.* 
7i,\  Anterior  upper  premolar   (pw')   well  developed; 

baculum  present Subgenus  SciURUS   (p.  48) 

h^.  Anterior  upper  premolar    (pm^)    vestigial — often 

absent;  baculum  absent Genus  Tamiasciueus  (p.  51) 

.9^  Notch  in  zygomatic  plate  of  maxillary  opposite  m\ 
h\  Second  upper  premolar  {pni*)  broader  than 

long Subgenus  Hesperosciueus   (p.  49) 

h^.  Second  upper  premolar  {pm*)   not  broader  than 
long. 
i^.  Interorbital  breadth   greater   than   postorbital 

breadth Subgenus  Otosciurus  (p.  50) 

f.  Interorbital    breadth    not    greater    than    post- 
orbital  breadth Subgenus  Neosciueus  (p.  48) 

Genus  MARMOTA:  Marmots 

Martnota  Blumenbach,  Handbuch  der  Naturgeschichte  1:  70,  1779   (type,  Mus 
marmota  Linnaeus). 

The  marmots,  woodchucks,  or  ground  hogs  attain  the  largest  size 
of  any  of  the  Sciuridae.  The  skull  is  nearly  flat  on  top,  the  tip  of 
the  rostrum  slightly  depressed ;  the  brain  case  is  very  broad,  the  zygo- 
matic arches  wide-spreading,  their  anterior  portion  thickened; 
the  postorbital  processes  are  very  broad,  not  greatly  depressed,  pro- 
jecting nearly  at  right  angles  to  the  axis  of  the  skull  at  about  the 
middle  portion  of  the  orbit. 

The  upper  molars  are  heavy,  subquadrate,  and  brachydont,  with 
heightened  inner  cones;  the  anterior  upper  premolar  is  about  one- 
third  as  large  as  pm'^;  pm*  is  about  as  long  as  broad,  or  slightly 
longer,  with  a  prominent  parastyle  separated  from  the  protoloph  by  a 
broad  valley;  the  parastyle  ridge  on  m^  and  m^  is  low  and  joins  the 
protocone  with  an  abrupt  change  of  direction ;  the  metaloph  on  pm'^, 
m^,  and  m^  is  more  or  less  interrupted;  on  m^  it  turns  backward  to 
join  the  heel.  The  lower  molars  are  heavy,  with  prominent  cones 
and  deep  valleys;  on  the  anterior  lower  premolar  the  protoconid 
and  paraconid  are  separated  by  a  broad  sulcus,  and  there  are  one  or 
two  small  cusplets  on  the  anterior  face  of  the  tooth  between  the  two 
principal  cusps. 

The  upper  incisors  are  heavy,  and  less  compressed  laterally  than 
in  Citellus,  their  anterior  face  smoothly  rounded. 


38 


NORTH  AMERICAN  FAUNA  tNo.  56 


Subgenus  MARMOTA 

Pocock  (1923a,  p.  1200)  has  divided  the  genus  Marmota  on  the 
presence  or  absence  of  the  pollex.  The  type  species— J/,  marmota^ 
of  Europe — apparently  differs  from  all  the  other  species  in  the  com- 
plete absence  of  this  digit.  Comparison  of  the  skulls  of  M.  marraota 
and  M.  monax  shows  no  distinguishing  characters  of  more  than 
specific  value. 

Subgenus  MARMOTOPS 

Marmotops  Pocook,  Zool.  Soc.  London  Proc.  1922:  1200,  1923   (type,  Marmota 
monax) . 

As  shown  by  Pocock  and  verified  by  examination  of  specimens  in 
the  United  States  National  Museum,  all  the  American  and  Eurasian 
species  except  M.  marmota  possess  a  rudimentary  thumb  (pollex) 
bearing  a  broad,  flat  nail.  This  character  is  considered  to  be  of  sub- 
jreneric  value. 

Genus  CYNOMYS:  Prairie  Dogs 

Cynomys  Rafinesque,  Amer.  Monthly  Mag.  2:  45,  1817  (type,  Cynomys  socialis 
Rafinesque  =  C.  ludovicianus) . 

The  prairie  dogs  are  more  closely  related  to  the  ground  squirrels 
{Citellus)  than  to  the  marmots.  The  skull  of  Cynomys  resembles 
that  of  Citellus  parryii  rather  closely  in  general  contour,  but  differs 
in  several  important  characters.  The  molariform  teeth  are  very 
heavy,  much  broader  than  long,  high  crowned  on  inner  side ;  the  inner 
roots  of  m^  and  m^  are  greatly  enlarged  and  the  outer  roots  corre- 
spondingly reduced;  the  upper  tooth  rows  are  strongly  convergent 
posteriorly,  instead  of  being  nearly  parallel  as  in  Marmota  and  Citel- 
lus. The  anterior  premolar  is  always  very  large — more  than  half  the 
size  of  pm* — its  outline  oval  rather  than  subcircular.  The  trans- 
verse ridges  on  m^  and  m"^  are  more  crowded  than  in  Citellus^  with  a 
relatively  shallow  valley  between ;  on  the  last  upper  molar  the  crown 
pattern  is  more  complicated,  having  two  complete  transverse  ridges 
and  an  additional  ridge  extending  from  the  mesostyle  partly  across 
the  tooth;  the  last  lower  molar  is  decidedly  longer  than  mo  and  the 
crown  pattern  is  more  complicated  than  the  corresponding  tooth  in 
Citellus;  this  tooth  has  an  enlarged  heel,  with  a  greater  develoj)ment 
of  the  enamel  folds,  which  extend  from  the  inner  side  and  practically 
fill  the  talonid  basin  (pi.  12;  pi.  14,  G;  pi.  17,  G;  pi.  20,  A). 

The  baculum  of  Cynomys  ludovicianus  resembles  that  of  the 
ground  squirrels  in  shape;  it  is  4.9  mm  in  length,  the  shaft  rather 
stout  and  greatly  thickened  at  the  proximal  end;  the  distal  end  is 
expanded  in  the  shape  of  a  deep  scoop,  the  edges  of  which  are  irreg- 
ularly denticulate;  the  shaft  is  continued  on  the  under  side  of  the 
scoop  as  a  narrow  process  (pi.  13,  M) . 

Subgenus  CYNOMYS 

Characters  as  given  above  for  the  genus ;  further  characterized  by 
the  relatively  heavy  jugal,  which  at  the  angle  of  the  ascending  branch 
is  thickened  and  shows  a  prominent  triangular  process. 

Subgenus  LEUCOCROSSUROMYS 

Leucocrossuromys  Hoixistee,  North  Amer.  Fauna  40:  23,  1916  (type,  Spermo- 
philus  gunnisoni  Baird). 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  39 

The  skull  of  this  subgenus  is  similar  to  that  of  typical  Cynomys; 
the  general  shape  of  the  occipital  region,  viewed  from  behind,  is 
elliptical-oval;  the  jugal  is  relatively  "weak,  thin,  and  flat,  the  outer 
surface  at  angle  of  ascending  branch  only  very  slightly  thickened, 
the  margin  rounded,  not  triangular"  (HoUister,  op.  cit.). 

Genus  CITELLUS:  Ground  Squirrels 

Citellus  Oken,  Lehrbuch  der  Zoologie  (3)  2:  S42,  1816  (type,  Mus  citellus  Lin- 
naeus). 

The  ground  squirrels  are  represented  in  North  America  by  31 
species  arranged  in  8  subgenera  and  12  well-marked  groups,  easily 
distinguished  by  their  color  pattern.  These  comprise  the  species 
commonly  referred  to  typical  Citellus  (in  which  are  represented  sev- 
eral minor  groups) ;  the  striped  and  the  spotted  ground  squirrels 
{Ictidomys) ;  Franklin's  ground  squirrel  {PoliociteUus) ;  rock  squir- 
rels {Otospermophilus)  \  ring-tailed  ground  squirrels  {N otocitellus) 
antelope  squirrels  {Ammospermophilus) ;  desert  ground  squirrels 
(Xerospermophilus) ,  containing  only  two  plain-colored  forms;  and 
mantled  ground  squirrels  {Callospermophilus). 

Some  of  these  groups  now  rank  as  genera,  others  as  subgenera; 
Ammospermophilus  and  Callospermophilus  apparently  have  been 
accorded  generic  rank  largely  by  reason  of  their  external  characters. 
Detailed  comparison  of  the  skulls  of  all  the  species  of  ground  squir- 
rels shows  them  to  be  closely  related,  the  various  groups  differing  in 
relative  proportions  of  the  skull  and  teeth. 

The  molars  vary  in  height  of  crown  from  the  hypsodont  type  found 
in  typical  Citellus  to  the  brachydont  type  found  m  Otospermophilus^ 
Callospermophilus^  and  Ammospermophilus ;  the  anterior  premolar 
(always  present)  varies  from  the  large  functional  tooth  found  in  G. 
parryii — fully  one-third  as  large  as  the  adjoining  premolar  (pm*) — 
to  the  small,  peglike  tooth  of  Ammospermophilus,  which  is  scarcely 
one-tenth  as  large  as  the  next  premolar,  and  but  little  larger  than  the 
corresponding  tooth  in  Eutamias. 

The  upper  incisors  vary  from  a  long,  slender,  forward-projecting 
type  found  in  C.  parryii  to  the  short,  stout,  recurved  teeth  of  C. 
armulatus,  which  in  this  character  strongly  resembles  some  of  the 
tree  squirrels. 

GENERIC  CHARAOTEBS 

The  genus  Citellus  differs  from  Sciurus  in  having  a  much  shal- 
lower brain  case;  the  zygomata  are  contracted  anteriorly,  the  an- 
terior portion  twisted  toward  a  horizontal  plane;  the  upper  surface 
of  the  jugal  is  without  a  prominent  process;  the  antorbital  foramen 
forms  a  canal,  oval  or  subtriangular  in  shape ;  the  molarif orm  teeth 
are  less  primitive  and  usually  much  more  hypsodont;  pm^  is  always 
present,  though  variable  in  size.  Citellus  differs  from  Cynomys  as 
follows :  Upper  molariform  tooth  rows  parallel  or  only  slightly  con- 
vergent posteriorly ;  upper  molars  relatively  lighter  and  less  hypso- 
dont; last  upper  molar  with  enamel  pattern  less  complicated,  the 
metaloph  present  in  some  species,  absent  in  others,  but  never  with  an 
additional  subsidiary  loph;  last  lower  molar  likewise  with  less  com- 
plicated enamel  folding,  the  talonid  basin  present,  as  in  m^  and  m^. 


40  NORTH  AMERICAN  FAUNA  INo.  56 

Subgenus  CITELLUS 

Type. — Mus  citellus  Linnaeus. 

CKANIAI,  CHABACTEBS 

Dorsal  profile  of  skull  moderately  convex;  parietal  ridges  faintly 
indicated ;  brain  case  subglobular,  about  as  broad  as  long ;  postorbital 
processes  long,  slender,  and  decurved;  zygomata  moderately  heavy, 
broadly  expanded  posteriorly,  narrowing  strongly  anteriorly;  antor- 
bital  foramen  large,  suborbicular. 

Molarif orm  tooth  rows  parallel  or  slightly  convergent  posteriorly ; 
upper  incisors  relatively  slender;  anterior  upper  premolar  (pm^) 
more  than  one-third  the  size  of  pm^,  bearing  a  simple,  functional, 
obliquely  transverse  ridge;  molars  hypsodont,  broader  than  long; 
transverse  ridges  on  pm*,  m^,  and  m^  forming  a  narrow  U ;  parastyle 
ridge  on  ni^  and  m^  very  low,  joining  protocone  with  an  abrupt 
change  of  direction  (almost  a  ri^ht  angle) ;  m^  with  posterior  loph 
obsolete  in  some  species,  present  m  others,  and  variable  in  some, 

A  series  of  12  specimens  of  O.  citellus — ^type  of  the  genus — from 
Hungary,  recently  acquired  through  the  cooperation  of  the  Hun- 
garian National  Museum,  makes  it  possible  to  define  the  characters 
of  the  type  species  in  comparison  with  the  American  species  of  the 
genus.  The  skull  of  C.  citellus  (pi.  14,  E;  pi.  17,  E;  pi.  20,  D)  is 
similar  in  general  to  that  of  O.  heldingi,  but  slightly  smaller  and 
more  weakly  built ;  dorsal  profile  moderately  convex ;  parietal  ridges 
slightly  indicated;  brain  case  subglobular,  about  as  broad  as  long; 
posterior  truncation  of  brain  case  nearly  vertical;  lambdoid  crest 
moderately  prominent;  paroccipital  processes  moderate;  interorbital 
breadth  somewhat  less  than  postorbital  constriction ;  postorbital  pro- 
cesses long,  slender,  and  decurved;  zygomata  moderately  heavy, 
broadly  expanded  posteriorly,  narrowing  strongly  anteriorly;  ros- 
trum narrow,  its  sides  nearly  parallel ;  nasals  narrowing  slightly  pos- 
teriorly, extending  slightly  beyond  nasal  branches  of  premaxillaries ; 
antorbital  foramen  large,  suborbicular;  incisive  foramina  short  and 
broad ;  molarif  orm  tooth  rows  slightly  convergent  posteriorly ;  ptery- 
goids long  and  slender;  auditory  bullae  moderately  inflated  and 
evenly  rounded,  without  external  meatus. 

Upper  incisors  slender,  nearly  perpendicular  to  basi-cranial  axis; 
molars  hypsodont,  broader  than  long ;  anterior  upper  premolar  (pm^) . 
more  than  one-third  the  size  of  pm^,  bearing  a  simple,  functional, 
obliquely  transverse  ridge;  pm*,  m^,  and  m^  with  high  transverse 
ridges  forming  a  narrow  U ;  parastyle  ridge  on  m^  and  m^  very  low, 
joining  protocone  at  almost  a  right  angle ;  metastyle  on  pm*,  m},  and 
m^  low  and  weakly  developed,  not  directly  joined  to  the  protocone; 
m^  with  posterior  ridge  (metaloph)  obsolete;  lower  molars  hypso- 
dont, the  anterior  cusps  much  higher  than  the  posterior,  with  a  dis- 
tinct narrow  transverse  ridge  joining  the  protoconid  with  the  par- 
aconid ;  prrii  with  the  two  anterior  cusps  separated  by  a  broad  sulcus. 

External  chabacteiss 

The  species  associated  in  the  typical  subgenus  Citellus  vary  greatly 
in  external  characters.  In  all  forms  the  ears  are  rather  low,  in  some 
but  little  raised  above  the  crown,  in  others  of  medium  height,  but 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  41 

not  pointed.  The  tail  may  be  about  half  the  length  of  the  body  or 
much  shorter.  The  coloration  varies  from  plain  to  mottled  or 
spotted. 

BACULAB   CHAEACTEES 

The  baculum  from  a  specimen  of  Citellus  heldingi  oregonus  is  3.5 
mm  in  length;  its  shaft  is  broad  at  the  base,  slightly  curved,  and 
narrowed  toward  the  tip,  which  is  shaped  like  a  spoon  with  a  crenu- 
late  border.  The  apex  of  the  shaft  appears  as  a  short  process  pro- 
jecting from  the  lower  surface  of  the  terminal  disk  (pi.  13,  Q). 

Subgenus  ICTIDOMYS 

Ictidomys  Allen,   Moiiog.  North  Ainer.  Rodentia,  p.  821,  1877    (type,  Sciurus 

tridecemlineatus  Mitchill). 
Ictidomoides  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  328,  1907  (type,  Sciurus  mexi- 

canus  Erxleben). 

As  originally  proposed  by  Allen  the  subgenus  Ictidomys  com- 
prised the  species  tereticaudus,  mexicanus^  trideceinlineatus,  and 
franklinii.  The  type  has  been  fixed  by  Merriam  (Allen,  1895a,  p. 
418)  as  Citellus  tridecemlineatus]  tereticaudus  has  been  removed  to 
another  subgenus  and  franklinii  is  here  made  the  type  of  a  new 
subgenus.  Ictidomoides^  proposed  by  Mearns  (1907,  p.  328)  for  C. 
mexicanus,  appears  to  be  inseparable  from  Ictidomys.  C.  spilosoma 
and  0.  perotensis  are  also  included  in  this  subgenus. 

CBANIAL  CHAKACTB3ES 

Ictidomys  differs  from  typical  Citellus  in  having  a  relatively  nar- 
rower brain  case;  the  rostrum  tapering  gradually;  upper  incisors 
relatively  stouter,  shorter,  and  distinctly  recurved;  anterior  upper 
premolar  relatively  much  smaller  (less  than  one-third  as  large  as 
pm*)^  its  crown  sometimes  developing  a  short  cutting  edge,  but  often 
appearing  as  a  single  cusp;  metaloph  of  pm*'^  m^,  and  m^  not  con- 
tinuous, the  metacone  separated  from  the  protocone  by  a  distinct 
sulcus;  on  m^  the  metaloph  is  obsolete  (pi.  14,  C ;  pi.  17,  G ;  pi.  20,  H). 

E3TEENAI,  CHARACTERS 

Body  rather  slender;  tail  distichous,  60  to  80  percent  of  the  head 
and  body;  ears  short  and  broad,  rising  but  little  above  the  crown; 
claws  on  front  feet  long  and  slender,  the  third  longest,  the  second 
and  fourth  about  equal,  the  fifth  much  shorter;  thumb  very  short, 
but  bearing  a  rudimentary  claw.  Claws  on  hind  feet  shorter  and 
stouter,  the  first  very  short,  the  fifth  somewhat  longer,  second  and 
fourth  about  equal,  and  third  slightly  longer.  Cheek  pouches  of 
moderate  size;  mammae  usually  10  or  12:  pectoral,  f,  abdominal, 
f  or  f ,  inguinal,  \. 

The  pelage  in  this  subgenus  is  dense  and  soft,  and  of  moderate 
length.  Apparently  there  is  but  one  molt  annually,  occurring  in 
April  or  May,  but  its  progress  is  not  clearly  shown  by  any  of  the 
specimens  examined. 

The  color  pattern  in  the  type  species  consists  of  a  series  of  alter- 
nating light  and  dark  stripes,  with  whitish  spots  in  the  middle  of 


42  NORTH  AMERICAN  FAUNA  [No.  56 

the  dark  stripes;  in  G.  mexicanus  the  dorsal  stripes  are  all  broken 
into  spots;  G.  spilosoma  and  G.  perotensis  are  irregularly  spotted  on 
a  plain  background. 

BACTDIAE  CHABACTEES 

The  baculum  of  G.  tridecemlineatus — ^the  type  of  this  subgenus — 
consists  of  a  nearly  straight  shaft  4.9  mm  long,  much  thickened  at 
the  proximal  end,  tapering  rather  abruptly,  the  distal  end  upturned 
and  widely  expanded  into  a  shallow  "scoop",  with  a  wide  cleft  in  the 
center ;  the  margin  of  the  scoop  on  either  side  with  shallow  crenula- 
tions ;  there  is  no  process  at  the  tip  of  the  shaft  (pi.  13,  N) . 

The  baculum  of  G.  mexicanus  is  similar  to  that  of  G.  tridecem- 
Uneatm,  but  the  tip  is  less  widely  expanded  and  more  sharply  up- 
turned on  the  sides,  thus  producing  a  deeper  hollow  in  the  center  of 
the  scoop.  The  tip  of  the  shaft  shows  as  a  process  from  the  under 
side  of  the  scoop.  As  in  G.  tridecemlineatits,  the  border  of  the  disk 
shows  slight  crenulations  (pi.  13,  0). 

POLIOCITELLUS,  enbgenns  nov. 

Type. — Arctomys  franklinii  Sabine. 

CBANIAX  CHARACTERS 

Gitellus  franklinii  differs  in  many  rather  striking  characters  from 
the  other  ground  squirrels  and  may  well  be  recognized  as  a  sub- 
genus. In  many  of  its  characters  it  furnishes  a  connecting  link 
between  Ictidomys  and  Otospermophilus.  It  differs  from  Gitellus 
in  the  general  contour  of  the  skull,  which  is  relatively  long  and  nar- 
row, with  the  superior  outline  flattened  and  the  rostrum  not  pinched 
in  at  base.  The  zygomata  are  less  widely  expanded  than  in  Gitellus 
cr  Otosjyertnophilus ;  the  interorbital  region  is  much  longer  than  hi 
Gitellus^  much  as  in  Otospermophilus  but  relatively  narrower;  its 
border  is  usually  without  a  notch,  the  supraorbital  foramen  closed 
in  the  majority  of  specimens;  the  postorbital  processes  are  much  as 
in  Gitellus — slenderer  than  in  Otospermophilus — ^the  upper  incisors 
resemble  those  of  Otospermophilus^  and  are  stouter  than  those  of 
Gitellus;  the  upper  molars  are  similar  to  those  of  Otospermophilus^ 
but  somewhat  more  hypsodont,  the  accessory  tubercles  on  rn}  and  m^ 
more  prominent.  Compared  with  Gitellus  the  upper  molars  are  much 
lower-crowned  and  relatively  longer  (antero-posteriorly)  ;  the  para- 
style  ridge  rises  gradually  to  join  the  protocone,  without  an  abrupt 
change  in  direction;  the  transverse  ridges  are  more  widely  spaced 
and  the  metaloph  on  pm^^  m^,  and  m^  is  frequently  discontinuous;  on 
m^  the  metaloph  is  absent.  The  anterior  upper  premolar  {pm^)  is 
peculiar,  usually  showing  two  distinct  cusps,  the  outer  one  being 
higher  than  the  inner.  This  tooth  is  relatively  larger  than  in  Oto- 
speTTYhophilus  but  not  as  large  as  in  Gitellus^  being  one-fourth  to  one- 
third  the  size  of  pm"  (pi.  14,  B;  pi.  17,  B;  pi.  20,  E). 

EXTEENAL  CHABACTEES 

Body  and  limbs  slender,  resembling  those  of  the  tree  squirrels 
{Sciurus) ;  tail  more  than  half  as  long  as  the  head  and  body,  some- 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  43 

what  bushy ;  ears  low  and  evenly  rounded ;  coloration  uniform,  with 
indistinct  mottling;  mammae  10  or  12;  pectoral,  f ;  abdominal,  j-  or  f; 
inguinal,  f ;  cheek  pouches  small;  claws  stout,  slightly  curved. 

The  pelage  is  dense  and  rather  harsh;  plain  or  dappled;  the 
method  and  time  of  molting  is  not  evident  from  examination  of 
museum  specimens. 

BACULAB  CHABACTEES 

Baculum  4.3  mm  in  length,  shorter  and  stouter  than  that  of  G.  tri- 
decemlineatus^  the  shaft  sharply  bent  upward  near  the  terminal  disk, 
which  is  1.6  mm  broad,  shaped  like  a  saucer  and  without  pronounced 
crenulations  on  its  margin.  The  tip  of  the  shaft  projects  from  the 
under  side  of  the  disk  as  a  flattened  process  having  a  shallow  sulcus 
on  the  anterior  border  (pi.  13,  P). 

Subgenus  OTOSPERMOPHILUS 

OtospermopMlus  Brandt,  Bull.  Class.  Phys.-Math.  Acad.  Imp.  Sci.  St.  Peters- 
bourg,  2:  379,  1844  (type,  Sciurus  grammurus  Say). 

The  subgenus  Otospermophilus^  proposed  for  the  "eared  spermo- 
philes",  comprising  the  rock  squirrels  {heecheyi,  grammurus^  etc.), 
G.  {C ollosperTno'philus)  lateralis,  and  G.  (Ictidomys)  mexicanus^ 
has  been  restricted  by  elimination  to  the  Gitellus  heecheyi-graniTnu- 
rus  group. 

CRANIAL   CHAKACTEBS 

Skull  similar  to  that  of  Gitellus  {Poliocitellus)  franklinii,  but 
brain  case  broader  and  relatively  shallower;  interorbital  region 
broader;  rostrum  short  and  broad,  tapering  gradually;  antorbital 
foramen  narrowly  oval.  Upper  incisors  stout,  recurved;  anterior 
upper  premolar  relatively  small,  about  one-sixth  the  size  of  pm*; 
upper  molars  low-crowned,  nearly  quadrate;  transverse  ridges  on 
pm*,  m^,  and  m^  more  widely  separated  than  in  typical  Gitellus  and 
less  completely  united  with  the  protocone ;  posterior  loph  on  m}  and 
m^  frequently  broken  up  into  one  or  two  islandlike  cusps;  m^  with- 
out metaloph  (pi.  15,  /^;  pi.  18,  F\  pi.  21,  G). 

EXTEBNAL  CHABACTEBS 

Body  and  limbs  moderately  slender;  ears  larger  than  in  Polio- 
citellus or  typical  Gitellus;  tail  about  two-thirds  the  length  of  the 
head  and  body,  somewhat  bushy;  cheek  pouches  large. 

BACTJLAB  CH^VEACTERS 

The  baculum  of  a  specimen  of  0.  variegatus  grammurus  (pi.  13, 
G)  from  Tucson,  Ariz.,  is  similar  to  that  of  G.  {Gitellus)  heldingi 
oregonus  but  is  slightly  longer  (4.5  mm)  with  fewer  "teeth"  on 
the  terminal  portion ;  the  shaft  is  nearly  straight,  and  its  tip  projects 
beyond  the  triangular-shaped  "spoon"  as  a  prominent  j)rocess. 
Another  specimen  (pi.  13,  H)  differs  from  the  one  just  described  in 
being  more  strongly  curved,  and  instead  of  a  spoon-shaped  disk  at 
the  tip  the  baculum  divides  into  three  blunt  processes.  This  sug- 
gests that  in  a  larger  series  other  variations  may  occur.  A  baculum 
of  G.  V.  huchleyi  (pi.  13,  /)  resembles  that  of  G.  v.  grammurus,  but 
the  disk  is  narrower. 


44  NORTH  AMERICAN  FAUNA  [No.  56 

NOTOCITELLUS,  subgenus  nov. 

Type. — Spermophilus  annulatus  Audubon  and  Bachman. 

CEANIAI,  CHABACTEES 

Skull  similar  to  that  of  Citellus  {Otospermo'philus)  heecheyi  but 
interorbital  region  relatively  broader;  supraorbital  foramen  always 
closed;  rostrum  short,  the  nasals  relatively  broader  posteriorly; 
zygomata  less  widely  expanded  posteriorly;  incisors  relatively 
shorter  and  thicker  antero-posteriorly ;  molariform  teeth  as  in  Oto- 
spermophilus.  Compared  with  G.  {Poliocitellus)  franklinii  the 
skull  of  Notocitellus  is  relatively  broader  in  the  interorbital  region, 
the  rostrum  is  shorter  and  broader,  and  the  molariform  teeth  are 
lower  crowned,  with  p^  relatively  smaller  (pi.  26,  D\  pi.  31,  D). 

EXTEENAL  CHAEACTEBS 

Form  slender;  tail  more  than  two-thirds  the  length  of  head  and 
body,  distichous,  not  bushy ;  feet  long  and  slender ;  claws  sharp,  re- 
curved ;  ears  shorter  and  less  pointed  than  in  Otospermophilus^  their 
superior  margin  evenly  rounded.  Pelage  thin  and  somewhat  harsh. 
Color  pattern  plain.  Cheek  pouches  large  {fide  Audubon  and  Bach- 
man). 

Subgenus  AMMOSPERMOPHILUS 

AmmospermopMlus   Merriam,    Biol.    Soc.    Wash.    Proc.    7 :  27,   April   13,    1892 
(type,  Tamias  leucurus  Merriam). 

CEANIAL  CHAEACTEES 

Skull  similar  to  that  of  Otospermophilus,  but  brain  case  more  rec- 
tangular, relatively  broader  at  the  posterior  end,  and  distinctly 
flattened  on  the  upper  surface;  lambdoid  crest  much  reduced;  audi- 
tal  bullae  relatively  larger;  zygomata  appressed,  only  slightly  ex- 
panded at  posterior  end. 

This  subgenus  agrees  with  Otospermophilus  in  the  shape  of  the 
antorbital  foramen  and  in  the  attachment  of  the  maxillary  roots 
of  the  zygomata.  The  postorbital  processes  are  small  and  slender; 
the  upper  incisors  are  stout  and  recurved  much  as  in  O.  adocetus; 
the  molariform  teeth  are  essentially  like  those  of  Otospermophilus; 
the  anterior  upper  premolar  is  a  small,  simple,  peglike  tooth,  but 
little  larger  than  the  corresponding  tooth  in  Eutamias  (pi.  15,  E ; 
pi.  18,  ^/pl.  21,  Z>). 

EXTEENAL  CHAEACTEES 

Form  as  in  most  of  the  small  ground  squirrels;  legs  rather  short, 
tail  about  half  the  length  of  the  body,  distichous,  well-haired;  ears 
short,  broad  and  rounded;  cheek  pouches  large;  mammae,  10.  The 
color  pattern  consists  of  a  uniform  background,  with  a  single  lon- 
gitudinal white  stripe  on  each  side. 

ilBACULAE  CHAEACTEBS 

The  baculum  resembles  that  of  the  subgenus  Citellus;  the  prox- 
imal end  of  the  bone  is  thickened  and  laterally  expanded ;  the  shaft 
is  straight  and  slender ;  ih&  distal  end  is  bent  at  right  angles  to  the 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  45 

shaft,  and  expanded  into  the  shape  of  a  shallow  scoop,  the  edges  of 
which  are  crenulate.  Two  specimens  measured,  respectively,  1.5 
nmi  and  2.2  mm  in  length  (pi.  13,  K  and  Z). 

Subgenus  XEROSPERMOPHILUS 

Xerospermophilus  Merriam,  Biol.  Soc.  Wash.  Proc.  7:27,  April  13,  1892  (type, 
Spermophilus  mohavensis  Merriam). 

CEANIAL  CHARACTERS 

Skull  short  and  broad,  similar  in  general  shape  to  that  of  Citellus 
townsendii  inollis  but  relatively  broader  in  the  interorbital  region; 
postorbital  processes  shorter,  broad  at  base,  rapidly  tapering  to  a 
point ;  rostrum  short  and  broad,  tapering  gradually ;  brain  case  broad 
and  slightly  flattened;  zygomata  stout  and  moderately  expanded; 
upper  incisors  moderately  stout  and  slightly  recurved ;  molars  brachy- 
dont  (much  as  in  Otospermophilus) ;  ni^  and  ni-  slightly  broader  than 
long,  the  transverse  ridges  rather  widely  spaced ;  anterior  upper  pre- 
molar small,  less  than  one-fourth  the  size  of  ■pm'^\  audital  bullae 
moderately  inflated. 

Compared  with  AmmospermopJdlus  this  subgenus  differs  in  hav- 
ing a  shorter  brain  case ;  heavier  zygomata ;  interorbital  region  nar- 
rower; antorbital  foramen  broader  and  more  orbicular;  anterior  up- 
per premolar  relatively  larger ;  postorbital  processes  stouter ;  audital 
bullae  smaller  (pi.  14,  Z>;  pi.  17,  D;  pi.  20,  5). 

EXTERNAL  CHARACTEJES 

Body  stocky;  feet  stout;  claws  long,  sharp,  curved;  soles  densely 
haired;  palms  naked;  thumb  rudimentary^  bearing  a  broad  nail; 
teats,  10;  ears  very  low — a  mere  rim — tail  40-60  percent  of  the 
body  length,  somewhat  cylindrical,  well  haired,  but  appearing  terete 
when  worn;  pelage  soft  and  silky  when  fresh,  harsh  when  worn; 
coloration  plain. 

BACULAE  CHARACTERS 

The  baculum  of  Citellus  tereticaudus  is  similar  to  that  of  C. 
grammurus,  but  shorter,  measuring  3.5  rnm  in  length;  the  shaft  is 
much  enlarged  at  the  base  and  slightly  curved  upward;  the  tip 
broadens  out  to  form  a  nearly  circular  "spoon"  with  pronounced 
crenulations  on  the  margin;  the  tip  of  the  shaft  projects  well  be- 
yond the  border  of  the  disk  on  the  under  side  (pi.  13,  R). 

Subgenus  CALLOSPEKMOPHILUS 

Callospermophtlus  Merriam,  Biol.  Soc.  Wash.  Proc.  11:  189,  July  1,  1897  (type, 
ScAurus  lateralis  Say). 

CRANIAL  CHARACTERS 

Skull  very  similar  in  general  shape  and  in  proportions  to  that  of 
Otospermophilus^  but  upper  incisors  relatively  slenderer  and  less 
chiseled  off  on  inner  face ;  molarif orm  teeth  not  appreciably  different. 
Compared  with  Notocitellus :  Skull  relatively  narrower  interorbitally, 
the  supraorbital  foramen  opening  into  the  orbit;  rostrum  relatively 
narrower;  upper  incisors  decidedly  slenderer,  zygomata  more  widely 


46  NORTH  AMERICAN  FAUNA  [No.  56 

spread  posteriorly;  incisive  foramina  relatively  larger  (pi.  14,  A] 
pi.  17,  A;  pi.  20,  G). 

EXTEENAL  CHARACTERS 

Body  rather  stout ;  legs  short ;  tail  usually  more  than  half  as  long 
as  the  head  and  body  (about  one-third  as  long  in  Gitelhis  madren- 
sis),  distichous,  well  haired,  ears  large,  rounded  on  superior  margin 
(height  from  notch,  13  to  18.5  mm) ;  claws  slender,  sharp,  recurved; 
thumb  rudimentary,  bearing  a  short,  broad  nail ;  cheek  pouches  large ; 
mammae  8  or  10.  The  color  pattern  consists  of  a  longitudinal  white 
stripe  on  each  side  of  the  back,  bordered  on  one  or  both  sides  with  a 
black  stripe. 

BAOtTLAE    CHABACTERS 

The  baculum  is  a  tiny  bone,  2  mm  in  length,  irregularly  spatulate 
in  shape.  It  has  been  dissected  out  in  only  one  instance,  and  may  not 
always  be  present  (pi.  13,/). 

CHIPMUNKS 

The  chipmunks  (genera  Tamias  and  Eutamias)  are  more  nearly 
related  to  the  ground  squirrels  than  to  the  tree  squirrels.  The  essen- 
tial characters  distinguishing  these  two  genera  from  Citellus  (includ- 
ing all  the  subgenera)  are  as  follows:  Absence  of  an  antorbital 
canal,  the  antorbital  foramen  being  a  relatively  large  opening  in  the 
zygomatic  process  of  the  maxillary ;  the  anterior  border  of  the  zygo- 
matic notch  in  the  maxillary  is  opposite  pmJ^  instead  of  m}  as  in  all 
the  ground  squirrels;  the  transverse  ridges  on  m}  and  mr  are  not 
parallel,  the  posterior  loph  being  slightly  divergent  externally. 

Genus  TAMIAS:  Eastern  Chipmunks 

Tamias  Illiger,  Prodromus  Systematis  Mammalium  et  Avium,  p.  83,  1811  (type, 
Sciurus  striatus  Linnaeus). 

In  general  contour  the  skull  of  Tamias  most  nearly  resembles  that 
of  Citellus  {Notocifellus)  annulatus.  It  differs  from  it  and  from  all 
the  ground  squirrels  in  the  absence  of  pm^ ;  in  the  shape  and  position 
of  the  antorbital  foramen;  and  in  the  attachment  of  the  anterior 
root  of  the  zygomata.  The  posterior  border  of  the  zygomatic  plate 
of  the  maxillary  is  opposite  the  extreme  posterior  part  of  pm^  or 
sometimes  the  anterior  edge  of  m?-. 

The  superior  outline  of  the  skull  is  flat,  and  the  brain  case  is  shal- 
low; the  upper  incisors  are  short,  moderately  stout,  and  slightly 
recurved.  The  molars  are  low  crowned,  the  cusps  wide  spaced,  with 
slightly  developed  subsidiary  cusplets  between  the  primary  cusps 
(pi.  15,  5;  pi.  18,  B;  pi.  21,  E). 

The  color  pattern  consists  of  five  blackish  and  two  whitish  longi- 
tudinal stripes  on  the  dorsal  area ;  a  median  black  stripe  is  bordered 
on  each  side  with  a  broad  band  of  gray  or  tawny  about  twice  the 
width  of  the  median  stripe ;  on  either  side  of  these  dorsal  bands  are 
a  pair  of  shorter  blackish  stripes  with  a  whitish  stripe  between  them. 

The  baculumj  of  Tamias  striatus  is  about  4.5  mm  m  length,  nearly 
straight,  but  upturned  at  the  tip  and  slightly  expanded  into  the  shape 
of  a  narrow  spoon  or  scoop,  with  a  slight  median  ridge  on  the  under 
surface  (pi.  13,  A  and  B). 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  47 

Genus  EUTAMIAS:  Western  Chipmunks 

Eutamias  Trouessart,  Bull.  Soc.  d'Etudes  Sci.  d' Angers  10  (1)  :  86,  1880  (type, 
Sciurus  striatus  asiaticus  Gmelin). 

The  western  chipmunks  are  closely  related  to  the  eastern  chip- 
munks {Tamias).  The  genus  occurs  also  in  eastern  Asia,  and  the 
American  species  show  some  distinctive  group  characters,  considered 
of  subgeneric  value. 

Compared  with  Tamias^  the  skull  of  Eutamias  has  the  rostrum 
shorter  and  more  abruptly  constricted  at  the  base;  the  brain  case  is 
smoothly  rounded,  slightly  flattened  or  moderately  inflated ;  the  pal- 
ate is  relatively  shorter,  terminating  on  the  plane  of  last  molars  or 
but  little  posterior  to  it ;  the  notch  in  the  zygomatic  plate  of  the  max- 
illary projects  slightly  more  forward,  usually  being  opposite  the 
middle  or  posterior  part  of  /?m'^;  the  audital  bullae  are  relatively 
large;  the  upper  incisors  show  numerous  longitudinal  striations, 
'  which  in  some  species  are  well-defined  grooves ;  the  molarif orm  teeth 
are  much  as  in  Tamias^  but  the  anterior  premolar  {jpm^')  is  always 
present  as  a  small  peglike  tooth.  The  color  pattern  is  distinctive, 
consisting  of  five  blackish  and  four  whitish  longitudinal  stripes,  all 
of  approximately  equal  width  (pi.  15,  C\  pi.  18,  G\  pi.  21,  H). 

Subgenus  EUTAMIAS 

The  type  of  Eutamias  is  E.  asiaticus  of  eastern  Asia.  The  cranial 
characters  distinguishing  this  subgenus  from  the  American  sub- 
genus Neotamias  are  as  follows:  Interorbital  constriction  slight  (as 
in  Tamias) ;  postorbital  processes  broad  at  base,  tapering  to  a  point 
(much  as  in  Tamias)  ;  antorbital  foramen  large,  suborbicular  (as  in 
Tamias)  ;  lambdoidal  crest  moderately  developed;  upper  molariform 
tooth  rows  slightly  convergent  posteriorly  (as  in  Tamias) ;  palate 
short,  ending  about  on  plane  of  last  molars.  In  several  of  its  char- 
acters this  subgenus  resembles  Tamias  more  than  it  does  the  Ameri- 
can Neotamias. 

The  baculum  of  E.  asiaticus  (one  specimen)  differs  from  that  of 
the  American  species  of  Neotamias  in  being  much  more  slender.  It 
is  5  mm  in  length  and  tapers  gradually  from  base  to  tip;  the  distal 
portion  is  upturned  in  an  even  curve  and  slightly  flattened,  but  with- 
out ridges  (pi.  13,  C). 

Sabgenns  NEOTAMIAS 

Neotamias  Howell,  North  Amer.  Fauna  52:  26,  1929   (type,  Tamias  asiaticus 
merriami  Allen). 

The  American  members  of  the  genus  Eutamias  present  a  number 
of  characters  distinguishing  them  from  the  typical  members  of  the 
genus,  which  are  confined  to  Asia.  The  postorbital  processes  are  nar- 
rower at  the  base  and  much  slenderer  throughout;  the  interorbital 
constriction  is  more  pronounced;  the  lambdoidal  crest  less  strongly 
developed;  the  antorbital  foramen  smaller  and  narrowly  oval  rather 
than  orbicular ;  the  palate  ends  slightly  posterior  to  the  plane  of  the 
last  molars;  the  upper  tooth  rows  are  more  nearly  parallel.  The 
ears  are  relatively  longer  and  more  pointed. 

The  baculum  in  the  members  of  this  subgenus  differs  from  that 
of  both  Tamias  and  typical  Eutamias;  specimens  examined  of  six 


4g  NORTH  AMERICAN  FAUNA  [No.  56 

species  show  essential  similarity  in  form  but  some  variation  in  size. 
In  a  specimen  of  E.  quadrivittatus  f rater  (pi.  13,  E)^  the  baculum 
resembles  a  human  leg  in  general  shape;  it  is  3.8  mm  in  length, 
thickest  at  the  proximal  end,  and  tapers  gradually  to  the  tip  with 
a  sharp  bend  in  the  middle  of  the  shaft;  the  distal  end  is  bent 
upward  at  almost  a  right  angle,  expanded  and  flattened  in  the  shape 
of  a  human  foot,  with  a  prominent  narrow  ridge  in  the  center  of 
the  "instep."  In  a  specimen  of  E.  cinereicoUis  (pi.  13,  F)  the  bac- 
ulum is  4.7  mm  long  and  the  shaft  is  stouter  throughout.  Bacula 
of  E.  toiunsendii  sonomae  (pi.  13,  D)  and  E.  dorsalis  are  about  4.5 
mm  in  length  and  slenderer  than  in  the  other  species  examined. 

Genus  SCIURUS:  Tree  Squirrels 

Sciurus  Linnaeus,  Systema  Naturae   (10)   1:  63,  1758   (type,  Sclurus  vulgaris 
Linnaeus). 

The  North  American  tree  squirrels  are  all  remarkably  alike  in 
cranial  characters,  and  not  widely  different  from  the  typical  spe- 
cies— /Sciurus  vulgaris  of  Europe.  South  America  has  produced  a 
number  of  aberrant  groups  that  have  been  given  the  rank  of  genera 
(Allen,  1915,  p.  147).    These  have  not  been  studied  by  the  writer. 

As  already  pointed  out,  the  tree  squirrels  are  distinguished  from 
the  ground  squirrels  and  chipmunks  by  the  great  breadth  of  the 
interorbital  region  and  the  great  depth  of  the  brain  case;  the  zygo- 
mata are  nearly  parallel  to  the  axis  of  the  skull  and  nearly  vertical 
(not  twisted  as  in  Citellus),  with  an  angular  process  on  the  upper 
surface  of  the  jugal;  the  antorbital  canal  is  a  narrow  vertical  slit; 
the  upper  incisors  are  compressed  laterallj^  and  are  relatively  deep 
(much  like  those  of  Otospermophilus) .  The  molars  are  always  low 
crowned  and  simple.  The  anterior  upper  premolar  (pm^)  is  absent 
in  some  groups,  present  in  others,  but  always  very  small. 

Subgenus  SCIURUS 

The  typical  subgenus  is  not  represented  in  America. 

The  skull  of  the  type  species — Sciurus  vulgaris  of  Europe — ^is 
relatively  short  and  broad;  the  brain  case  strongly  deflected  at  pos- 
terior end;  a  shallow  depression  in  the  anterior  frontals  with  a 
swelling  on  posterior  frontals ;  zygomata  nearly  parallel,  moderately 
expanded ;  postorbital  processes  broad  at  base,  tapering  abruptly  to  a 
Ipng,  slender  point,  depressed  and  directed  backwards;  antorbital 
foramen  triangular,  broadest  at  base;  notch  in  maxillary  plate  of 
zygoma  opposite  pm^;  prn?  present,  but  very  small  and  not  rising 
to  the  level  of  pm^ ;  pmJ^  subquadrate,  narrowest  on  the  inner  side 
(pi.  16,  F;  pi.  19,  F;  pi.  22,  D). 

The  baculum  of  S.  vulgaris^  according  to  Thomas  (1915,  p.  384), 
is  essentially  like  that  of  S.  carolinensis. 

Subgenus  NEOSCIURUS 

Neosciurus  Trouessart,  Le  Naturaliste  2  (37):  292,  October  1880;  Catalogus 
Mammalium,  Rodentia,  p.  76,  1880  (part)  (type,  Sciurus  carolinensis 
Gmelin) . 

EcMnosciurus  Trouessart,  Idem  (type,  Sciurus  hypopyrrhus  Wagler  =  S.  aure- 
ogaster  hypopyrrhus). 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  49 

Baiosciurus  Nelson,  Wash.  Acad.  Sci.  Proc.  1:  31,  May  9,  1899  (type,  Scmrus 
deppei  Peters). 

The  skull  of  Sciurus  caroUnensis — the  type  of  the  subgenus  Neo- 
sciurus — does  not  differ  widely  in  general  shape  from  that  of  S. 
vulgaris  but  is  relatively  longer,  with  the  brain  case  shallower  and 
more  elongated  (less  globular)  and  the  rostrum  longer  and  rela- 
tively narrower;  the  postorbital  processes  are  shorter  and  stouter; 
the  notch  in  the  zygomatic  plate  of  the  maxillary  is  opposite  m^ 
(instead  of  pm*)  ;  pm^  is  present  but  not  strongly  developed;  pm* 
is  triangular  rather  than  quadrate  in  outline,  owing  to  the  greater 
production  of  the  parastyle  QdI.  15,  E;  pi.  18,  H;  pi.  21,  F) . 

In  S.  deppei  (type  of  Baiosciurus  Nelson),  prn^  averages  slightly 
more  quadrate  than  the  same  tooth  in  Neosciurus^  but  examination 
of  a  large  series  of  deppei  and  cai'olinensis  shows  that  the  character 
is  too  slight  and  inconstant  to  serve  as  a  basis  for  subgeneric 
distinction. 

Sciurus  aii/reogaster  hypopyrrhus  and  the  large  group  of  Mexican 
forms  associated  with  it  by  Nelson  in  the  subgenus  Echino sciurus 
differ  in  general  from  8.  carolinensis  in  having  a  shorter  and  rela- 
tively broader  rostrum  and  a  more  or  less  prominent  depression  in 
the  frontals;  these  differences,  however,  are  considered  too  slight 
to  warrant  recognition  of  the  group. 

The  baculum  of  Sciurus  carolinensis  is  apparently  closely  similar 
to  that  of  Sciurus  vidgaris.  It  is  10.5  mm  in  length,  the  shaft  stout, 
but  tapering  distally,  curved  upward  near  the  tip,  and  flattened  into 
the  shape  of  a  shallow  scoop  with  the  edges  rolled  up;  on  the  lower 
side  of  the  scoop  is  a  small,  blunt  process  (pi.  13,  S).  The  baculum 
of  S.  deppei  and  that  of  S.  adolphei  dorsalis  (pi.  13,  T)  agree  essen- 
tially with  that  of  S.  carolinensis. 

The  following  species  are  included  in  Neosciurus:  S.  carolinensis, 
S.  deppei,  S.  aureogasier,  S.  poliopus,  S.  yucatanensis,  S.  colliaei, 
S.  truei,  S.  sinaloensis,  S.  nelsoni,  S.  socialis,  S.  griseo/lavus,  S. 
goldmani,  S.  managuensis,  S.  boothiae,  S.  adolphei,  S.  thomasi,  and 
S.  variegatoides. 

Subgenus  HESPEROSCIURUS 

Hesperosciurus   Nelson,   Wash.   Acad.    Sci.    Proc.    1:    27,    May   9,    1899    (type, 
Sciurus  griseus  Ord). 

The  skull  of  Sciurus  griseus  resembles  that  of  S.  carolinensis  very 
closely,  except  that  it  is  larger ;  pm*  averages  slightly  more  quadrate 
(less  triangular),  but  examination  of  a  large  series  of  both  species 
shows  the  character  to  be  inconstant.  The  jugal  is  relatively  lighter 
(shallower)  and  viewed  from  beneath  shows  less  twisting  from  the 
vertical  plane  (pi.  15,  G;  pi.  18,  G;  pi.  21,  A). 

The  baculum  is  widely  different  from  that  of  Neosciurus,  re- 
sembling more  closely  that  of  S.  aberti.  The  bone  measuring  16.5 
mm  in  length,  is  moderately  curved  and  ends  in  a  blade  about  6.8 
mm  in  length,  with  a  curved  and  slightly  twisted  edge;  the  tip  of 
the  blade  is  a  blunt  point,  but  at  its  posterior  end  it  forms  a  short, 
sharp  hook  (pi.  13,  V). 

This  subgenus  comprises  but  one  species  S.  griseics,  of  the  Pacific 
coast  region  of  the  United  States. 

154970—38 4 


50  NORTH  AMERICAN  FAUNA  [No.  56 

Subgenus  OTOSCIURUS 

Otosciurus  Nelson,  Wash.  Acad.  Sci.  Proc.  1:  28,  May  9,  1899   (type,  Sciurus 
aberti  Woodhouse). 

In  general  shape  the  skull  of  Sciurus  aberti  closely  resembles  that 
of  S.  vulgaris;  pm^  is  relatively  larger  and  more  strongly  developed, 
the  crown  being  subject  to  wear  with  the  rest  of  the  molar  series; 
the  notch  in  the  zygomatic  plate  of  the  maxillary  is  opposite  the 
middle  portion  of  m}. 

Compared  with  Neosciurus,  this  subgenus  differs  in  having  the 
brain  case  and  interorbital  region  relatively  broader;  postorbital 
breadth  less  than  the  interorbital  breadth;  postorbital  processes 
larger  and  longer;  postorbital  notch  deeper;  pm?  more  strongly  de- 
veloped (pi.  16,  E;  pi.  19,  E;  pi.  22,  ^) . 

The  baculum  is  widely  different  from  that  of  typical  Sciurus  and 
of  S.  carolinensis,  and  bears  closer  resemblance  to  that  of  S.  griseus. 
It  is  a  nearly  straight  bone,  16.1  nun  in  length,  the  distal  portion  flat- 
tened laterally  into  the  shape  of  a  blade  with  a  curved  edge ;  on  the 
lower  side  of  the  blade  is  a  small  tubercle  (pi.  13,  W). 

The  species  included  in  Otosciurus  are:  S.  aberti^  S.  kaihahensis, 
S.  concolor,  and  S.  durangi. 

Subgenus  PARASCIURUS 

Parasciurus    Trouessart,    Le   Naturaliste    2    (37)  :    292,    October    1880    (type, 

Sciurus  niger  Linnaeus). 
Araeosciurus  Nelson,  Wash.  Acad.  Sci.  Proc.  1 :  29,  May  9,  1899. 

The  fox  squirrels  differ  from  the  other  North  American  squirrels 
(except  Guerlinguetus)  in  the  entire  absence  of  pm?.  Compared 
with  Neosciurus  the  skull  is  of  very  similar  shape,  the  brain  case 
somewhat  shallower  and  more  flattened;  the  frontals  are  slightly 
elevated  on  the  posterior  half ;  there  is  a  distinct  interorbital  notch ; 
the  notch  in  the  maxillary  plate  is  opposite  the  middle  or  hinder  part 
of  m^;  the  molariform  teeth  are  very  similar  to  those  of  Neosciurus 
(pi.  16,  (7/ pi.  19,  ^/ pi.  22,  .g). 

The  baculum  is  likewise  closely  similar  in  shape  to  that  of 
Sciurus  carolinensis  (pi.  13,  U). 

The  subgenus  comprises  the  following  species:  S.  niger,  S.  ari- 
sonensis,  S.  apache,  S.  alleni,  S.  nayaritensis,  and  S.  oculatus. 

Subgenus  GUERLINGUETUS 

Ouerlinguetus  Gray,  London  Med.  Repos.  15:  304,  1821   (type,  Sciurus  guer- 

Unguetus  Gray  =  S.  aestuans  Linnaeus). 
Mesosciurus  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  34 :  212,  1915.* 

The  skull  of  Sciurus  aestuans  ^  is  similar  in  shape  and  size  to  that 
of  Tamiasciurus  hudsonicus  but  has  a  deeper  and  more  highly  arched 
cranium;  the  rostrum  is  short  and  strongly  "pinched  in";  the 
zygomata  are  nearly  parallel  to  the  axis  of  the  skull ;  the  postorbital 
processes  are  short  and  slender;  the  hinder  portion  of  the  frontals 
is  swollen;  the  notch  in  the  maxillary  plate  is  opposite  the  hinder 
part  of  pm^  or  the  division  between  this  tooth  and  m^;  there  is  but 

*  Allen  proposed  Mesosciurus  as  a  genus  mainly  on  the  possession  of  eight  mammae 
instead  of  six,  as  in  Ouerlinguetus  ;  he  states  that  there  is  "no  very  marked  difference"  in 
cranial  or  dental  characters  between  these  two  groups. 

^  Comparisons  were  made  with  a  series  of  skulls  from  British  Guiana,  borrowed  from 
the  American  Museum  of  Natural  History  (nos.  34874,  42344,  48137,  48392). 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  51 

one  upper  premolar  (pm^),  which  is  subcircular  or  quadrate  in 
shape,  differing  thus  from  Parasciurus  and  Tamiasciuncs,  in  which 
this  tooth  is  subtriangular.  The  skull  differs  from  that  of  Parasciu- 
rus also  in  having  a  shorter  rostrum,  more  swollen  brain  case,  and  m 
the  position  of  the  notch  in  the  maxillary  plate  of  the  zygoma  (pi, 
16,  5/ ph  19,  5/ pi.  22,  F.) 

The  subgenus  GuerUnguetus  is  represented  in  North  America  by 
Sciurus  richmondi^  S.  hoffmanni^  and  ^S".  gerrardi. 

Genus  TAMIASCIURUS :  Red  Squirrels 

Tatniasciurus   Trouessart,    Le    Naturaliste   2    (37)  :    292,    October   1880    (type, 
Sciurus  hiidsonicus  Ersleben.) 

The  red  squirrels,  or  chickarees,  differ  from  typical  Sciurus  in  the 
vestigial  character  of  the  anterior  upper  premolar,  which  is  often 
absent  and  when  present  is  minute  and  never  functional,  being  cov- 
ered by  the  crown  of  pm'^.  The  superior  outline  of  the  skull  is  much 
flatter,  the  brain  case  shallower  and  not  strongly  deflected  posteri- 
orly; the  zygomata  are  less  expanded,  being  parallel  to  the  axis  of 
the  skull ;  the  postorbital  processes  are  much  shorter. 

Compared  with  S.  {Neosciunis)  caroUnensis,  T amiasciurns  differs 
in  the  (usual)  absence  of  pm^  and  in  having  the  notch  in  the  zygo- 
matic plate  of  the  maxillary  opposite  J9m*  (instead  of  m})\  the 
rostrum  is  relatively  shorter  and  broader,  and  tlie  zygomata  less 
expanded  (pi.  16,  D;  pi.  19,  D;  pi.  22,  E). 

Although  the  red  squirrels  exhibit  no  very  marked  cranial  differ- 
ences from  the  other  tree  squirrels,  the  reproductive  tract  of  the 
males  is  strikingly  different  from  that  of  their  relatives  in  the 
genus  Sciurus.  They  have  no  baculum,  and  the  penis  is  long  and 
slender,  tapering  to  a  point.  The  anatomy  of  T amiasciurus  hud- 
sonicus,  in  comparison  with  that  of  certain  other  sciurids,  has  been 
reported  on  by  Mossman  et  al.  (Mossman,  Lawlah,  and  Bradley,  1932, 
p.  119)  and  their  findings  are  summarized  as  follows: 

This  species  differs  much  more  fundamentally  from  the  sciurid  type,  such  as 
8.  carolinensis,  than  any  other  studied.  The  striking  differences  in  the  male 
are:  minute  Cowper's  glands  opening  into  the  urethra  in  the  bulb,  no  penile 
duct,  no  bulbar  gland,  a  true  urethral  diverticulum  in  the  bulb,  a  long  filiform 
penis,  and  no  os  penis.  The  seminal  vesicles  are  excessively  large.  Anal  glands 
are  present.  The  female  also  differs  from  other  female  Sciuridae  examined  in 
having  an  unusually  long,  coiled  vagina  during  oestrus. 

Genus  MICROSCIURUS:  Pygmy  Squirrels 

Microsciurus  Allen,  Amer.  Mus.  Nat.  Hist.   Bull.  7:  332,  Nov.  8,   1895    (type 
Sciurus  alfari  Allen). 

The  genus  Microsciurus  comprises  the  smallest  of  the  North  Amer- 
ican squirrels.  The  skull  is  highly  arched,  with  a  pronoiniced  swell- 
ing on  the  frontals  at  the  plane  of  the  postorbital  processes;  brain 
case  is  strongly  deflected  at  posterior  end;  rostrum  is  short  and 
broad ;  upper  incisors  project  forward  to  or  beyond  the  plane  of  the 
tip  of  nasals;  jugal  is  relatively  wide,  inferior  margin  abruptlv 
depressed  anteriorly  where  it  joins  the  maxilla;  pm^  is  well  devel- 
oped (pi.  15,  />;  pi,  18,  Z>;  pi.  21,  B). 

Included  in  this  genus  are  the  species  M.  alfari,  M.  hoqi/rfensis^ 
M.  isf.hmius,  and  M.  septentrionalis  in  Central  America,  and  others 
in  South  America, 


52  NORTH  AMERICAN  FAUNA  [No.  56 

Genus  SYNTHEOSCIURUS :  Pygmy  Squirrels 

Byntheosciurus  Bangs,  Mus.  Comp.  Zool.  Bull.  39:  25,  April  1902   (type,  Syn- 
theosciurus  brochus  Bangs). 

The  skull  of  Syntheosciurus  is  similar  to  that  of  Microsdurus  but 
Avith  cranium  more  highly  arched;  frontals  swollen;  upper  incisors 
projected  forward,  and  having  a  broad,  shallow  groove;  molariform 
teeth  relatively  large,  pm^  present,  reaching  the  crown  of  ^m*;  au- 
dital  bullae  small ;  postorbital  processes  slender. 

The  fur  is  woolly ;  ears  short,  broad,  and  densely  haired ;  whiskers 
rather  short ;  tail  round  and  bushy. 

The  genus  is  known  only  from  the  type  species,  occurring  in 
Chiriqui,  Panama  (pi.  16,  A  ;  pi.  19,  A ;  pi.  22,  G) . 

Genus  GLAUCOMYS:  Flying  Squirrels 

Glaticomys  Thomas,  Ann.  and  Mag.  Nat.  Hist.   (8)   1:  5,  January  1908  (type, 
Mus  volans  Linnaeus) . 

The  genus  Glaucomys,  which  comprises  the  American  flying 
squirrels,  differs  widely  in  cranial  characters  from  all  the  other  groups 
of  the  Sciuridae.  The  skull  resembles  that  of  Sciurus  in  the  great 
depth  of  the  brain  case  and  the  shape  of  the  zygomata,  which  are 
vertical  (not  twisted  as  in  the  ground  squirrels) ;  it  differs  from 
Sciurus  in  the  extreme  constriction  of  the  interorbital  and  postorbital 
regions  and  the  presence  of  a  deep  interorbital  notch ;  the  postorbital 
processes  are  slender  and  project  about  in  the  middle  of  the  temporal 
fossa;  the  incisors  are  rather  slender,  and  not  recurved  as  in  most 
of  the  tree  squirrels. 

The  skull  agrees  with  that  of  the  chipmunks  (Eutamias)  in  the  po- 
sition of  the  notch  in  the  maxillary  plate  of  the  zygoma,  which  is 
opposite  ^7?i*,  but  differs  from  them  and  agrees  with  the  ground 
squirrels  m  the  possession  of  an  antorbital  canal.  The  cusps  on  the 
outer  side  of  the  upper  tooth  row  are  higher  than  in  Sciurus  or 
Eutamias  and  are  without  subsidiary  cusplets;  pni^  is  present  and 
is  relatively  larger  than  in  Eutmnias;  ptn^  is  subquadrate,  nearly  as 
large  as  m^^  with  the  parastyle  ridge  rising  to  form  a  cusp;  the 
lower  molars  resemble  those  of  Eutamias  in  having  small  cusplets 
between  the  primary  cusps  (pi.  15,  A ;  pi.  18,  A ;  pi.  21,  C) . 

The  baculum  of  Glaucomys  volans  is  12.5  mm  in  length  and  rela- 
tively much  slenderer  than  in  Sciurus  \  the  shaft  is  twisted  at  the 
proximal  end,  and  the  distal  end  is  bifid;  the  distal  half  is  com- 
pressed on  one  side  into  a  thin  blade  reaching  to  the  tip  (pi.  13,  X). 


REVISION  OF  THE  GENUS  CITELLUS 

[For  generic  characters  see  p.  39] 

Citellus  Oken,  Lehrbuch  der  Zoologie  (pt.  3)  2:842,  1816,  (type,  Mus  citellus 
Linnaeus). 

Anisonyx  Rafinesque,  Amer.  Monthly  Mag.  2  (1)  :  45,  1817  (type,  Anisonyx 
irachiura  Rafinesque   (^Arctomys  coliiniManus  Ord)). 

Spermophilus  F.  Cuvier,  Dents  des  Mamm.,  p.  255,  1825,  (type,  "Mus  citillus 
Linn."). 

Spermophila  Richardson,  Parry's  Second  "Voyage,  App.,  p.  313,  1825. 

Spermophillus  Cuvier,  Diet  Sci.  Nat.  59 :  473.  1829. 

Spermatophihis  Wagler,  Nat.  Syst.  Amphibien,  p.  22,  1830. 

Spermophilis  Richardson,  Zool.  Voyage  H.  M.  S.  "Blossom" ;  Mamm.,  p.  12,  1839. 
■Citillus  Lichtenstein,  Darst.  neuer  oder  wenig  bekannt.  Sauget.,  pi  31,  fig.  2 
(not  paged),  1830. 

Colohotis  Brandt,  Bull.  Class.  Phys.-Math.  Acad.  Imp.  Sci.  St.  Petersbourg,  2 
(23  and  24)  :  366,  1844  (type,  Spennophilus  fulvus  Lichtenstein). 

Otocolotus  Brandt,  op.  cit.,  p.  382  {  =  Colodotis). 

Otospermophilus  Brandt,  op.  cit.,  p.  379  (type,  Sciurus  grammurus  Say). 

Colobates  Milne-Edwards,  Recherches  Hist.  Nat.  Mamm.  1 :  157,  1868-74. 

Ictidomys  Allen,  Monog.  North  Amer.  Rodentia,  p.  821,  1877  (type,  Sciurus 
tridecenilineatus  Mitchill) . 

XerospermopMlus  Merriam,  Biol.  Soc.  Wash.  Proc.  7:  27,  1892  (type,  Spermo- 
philus mohavensis  Merriam). 

Ammospermophilus  Merriam,  Biol.  Soc.  Wash.  Proc.  7:  27,  1892  (type,  Spermo- 
philus leucurus  Merriam). 

Callospermophilus  Merriam,  Biol.  Soc.  Wash.  Proc.  11:  189,  1897  (type,  Sciurus 
lateralis  Say). 

Ictidomoides  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  328,  1907  (type,  Sciurus  mexi- 
canus  Erxleben). 

Urocitellus  Obolenskij,  Comp.  Rend.  Acad.  Sci.  URSS.,  p.  188,  1927  (type, 
Spermophilus  eversmanni  Lichtenstein), 

HISTORY  AND  NOMENCLATURE 

The  ground  squirrel  of  central  Europe — the  ziesel — was  mentioned 
in  literature  as  early  as  1551,  by  Konrad  Gesner  (p.  835),  his  account 
being  the  principal  basis  of  the  Linnaean  name  3Ius  citelh(s,  the  type 
of  the  genus  Citellus. 

GENERIC  AND  SUBGENERIC  NAMES 

The  ground  squirrels  were  referred  by  most  of  the  earl}^  naturalists 
to  the  genus  Arctomys  {  =  Marmota)\  the  name  Spermophilus  was 
proposed  for  the  group  by  Cuvier  in  1825,  but  it  did  not  come  into 
general  use  until  about  5  years  later.  The  earlier  name  Citellus.  of 
Oken  (1816),  was  overlooked  until  revived  by  Allen  in  1902  (p.  373)  ; 
&ince  then  it  has  been  in  current  use.  Rafinesque  (1817,  p.  45)  intro- 
duced the  name  Anisonyx^  but  it  was  not  used  by  later  authors  until 
revived  for  a  short  time  by  Merriam  (1895a,  p.  18) ,  and  later  the  same 
year  was  found  to  be  preoccupied  (Merriam,  1895b,  p.  107), 

The  rock  squirrels  were  separated  by  Brandt  (1844,  p.  379)  as  a 
subgenus — Otospermophilus — and  they  have  been  regarded  since 
1907  as  a  genus  by  Mearns  and  certain  other  writers. 

53 


54  NORTH  AMERICAN  FAUNA  [No.  56 

In  the  same  paper,  Brandt  proposed  the  subgenus  Colobotis  to 
inckide  all  the  Old  World  species  known  to  him  and  also  richard- 
sonii,  ^'■hoodW^  {  =  tridecemlineatus) ,  and  franhlinii  of  North  Amer- 
ica. The  type  is  Spermo'philus  fulvus  Lichtenstein,  of  southern  Kus- 
sia.  The  name  Golohotis  has  been  used  in  a  subgeneric  sensa  by 
several  modern  authors  without  any  definite  idea  of  its  correct  ap- 
plication, due  to  the  lack  of  material  representing  the  type  species. 
Eecently,  through  the  kindness  of  L.  R.  Dice,  opportunity  has  been 
afforded  to  examine  a  single  skull  of  Citellus  fulvus  (pis.  14,  17,  20) 
from  Turkestan  (no.  57827,  Univ.  Mich.  Mus.  ZooL),  and  this  proves 
to  agree  in  essential  characters  with  Citellus  parryii  ablusus,  and  so 
far  as  can  be  determined  from  a  single  specimen  it  does  not  differ  in 
any  character  of  generic  value  from  O.  citellus,  the  type  of  the  genus. 

The  only  character  of  importance  distingushing  the  skull  of  Citel- 
lus fulvus  from  that  of  C.  citellus  (pis.  14,  17,  20)  appears  to  be  the 
presence  on  the  former  of  a  well-defined  metaloph  on  m^ ;  this  loph  is 
absent  on  the  series  of  12  adult  skulls  of  C.  citellus  from  Hungary, 
but  is  faintly  developed  on  a  single  young  individual  from  the  same 
region.  Unfortunately,  no  young  skulls  of  C.  fulvus  are  available, 
and  it  is  quite  possible  that  the  metaloph  of  m^  may  vary  in  the  ex- 
tent of  its  development,  as  it  does  in  numerous  North  American 
species. 

Of  the  North  American  species,  those  in  which  the  metaloph  on 
m^  is  most  strongly  developed  are  C.  pa7'ryii,  C.  osgoodi,  G.  columhi- 
anus,  G.  richardsonii,  C.  armatus,  and  G.  ivashingtoni.  In  G.  town- 
sendii  molUs  and  G.  idahoensis,  this  loph  is  absent  or  very  slightly 
developed,  while  in  C.  heldingi  it  is  sometimes  present,  sometimes 
absent. 

In  consideration  of  the  great  variability  of  tliis  character  in  the 
American  species,  and  in  the  absence  of  any  definite  group  charac- 
ters, it  is  considered  inadvisable  to  recognize  Colobotis  as  a  subgenus. 

Allen  (1877,  p.  821)  established  the  subgenus  Ictidomys,  but  with- 
out naming  a  type;  Merriam  (Allen,  1895a,  p.  418)  fixed  the  type  as 
Citellus  tridecemlineatus.  Merriam  (1892,  p.  27)  already  had  es- 
tablished the  subgenus  Xerospermophilus,  with  Spermophilus  mo- 
havensis  as  type,  and  the  subgenus  Ammos'permophilus  for  the 
antelope  ground  squirrels,  using  as  type,  SpermopMlus  leucurus.  The 
latter  group  since  1905  has  been  accorded  generic  rank  by  most  au- 
thors. In  the  present  study  it  is  again  reduced  to  subgeneric  rank, 
as  is  also  Callospennophilus,  proposed  by  Merriam  in  1897  (p.  189) 
as  a  subgenus  to  include  the  mantled  ground  squirrels,  and  since 
regarded  as  a  genus  by  many  authors. 

Mearns  (1907,  p.  328)  proposed  the  name  Ictidomoides  as  a  sub- 
genus for  the  species  Citellus  mexicanus,  but  this  is  now  considered 
the  same  as  Ictidomys. 

Obolenskij  (1927,  p-  188)  has  proposed  Urocitellus  as  a  subgenus, 
with  C.  eversinanni  as  the  type,  but  this  species  shows  no  cranial 
characters  to  separate  it  from  typical  Citellus. 

The  first  two  North  American  species  to  be  recognized  were  Citel- 
lus mexicanus  and  C.  variegatus^  both  described  by  Erxleben  in  1777, 
and  referred  to  the  genus  Sciurus.  The  former  name  was  adopted 
by  later  writers,  but  the  latter  was  allowed  to  lapse,  through  failure 
to  distinguish  the  animal  to  which  it  was  applied,  for  more  than  a 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  55 

century,  when  Nelson  (1898,  p.  898)  reinstated  it  by  showing  its  ap- 
plicability to  the  Mexican  rock  squirrel,  then  commonly  referred 
to  under  the  name  Spermo'philus  Tnacrourus. 

A  similar  fate  was  in  store  for  the  Columbian  ground  squirrel, 
fii-st  described  by  Lewis  and  Clark  and  named  Arctomys  columbianus 
in  1815  by  Ord  (pp.  292,  303),  and  again  in  1817,  Anisonyx  hrachi- 
ura,  by  Kafinesque  (p.  45).  Baird  (1875,  p.  336)  discussed  the  pos- 
sibility that  this  animal  might  be  a  prairie  dog — the  same  as  his 
Cynomys  gunnisoni — but  he  pointed  out  certain  important  differ- 
ences. Allen,  however  (1877,  p.  903),  unhesitatingly  pronounced  it  a 
prairie  dog  and  it  was  so  considered  until  Merriam  (1891,  p.  39), 
having  procured  specimens  from  the  type  region,  showed  it  to  be  a 
ground  squirrel. 

The  next  species  to  be  described  was  the  striped  ground  squirrel, 
named  Sciurus  tridecemllneatus  by  Mitchill  in  1821.  The  following 
year.  Sabine  renamed  this  animal  hoodii  and  described  also  two  other 
species,  the  Franklin's  and  Richardson's  ground  squirrels,  all  re- 
ferred by  him  to  the  genus  Arctomys. 

Long's  expedition  to  the  Rocky  Mountains  in  181^20  resulted  in 
the  discovery  of  two  new  species,  Citellus  grammurus  and  G.  lateralis, 
both  described  by  Say  in  1823  in  the  genus  Sciurus. 

Richardson,  in  1825,  described  the  big  northern  ground  squirrel, 
O.  parryii,  in  the  genus  Arctomys,  and  in  1829,  two  supposed  new 
varieties  of  that  species,  erythrogluieia  and  phaeognatha;  erythro- 
gluteia  later  proved  to  be  a  synonym  of  columbianus  and  phaeog- 
natha  a  synonym  of  parryii.  The  same  year  he  named  two  species 
from  the  west  coast  region,  heecheyi  and  douglasii. 

In  1833,  Bennett  described  the  Mexican  spotted  ground  squirrel, 
C.  spilosoma,  and  the  Mexican  rock  squirrel  under  the  name  Spermo- 
philus  macrourus ;  the  latter  name,  however,  was  later  found  to  be  a 
synonym  of  C.  variegatus. 

Bachman,  in  1839,  described  Citellus  toionsendii  from  the  plains 
of  the  Columbia,  but  the  type  specimen  soon  became  so  discolored 
with  grease  that  its  true  characters  could  not  be  seen,  and  as  a  result 
the  name  townsendii  has  been  misapplied  by  most  recent  authors  (see 
explanation  on  p.  62). 

Audubon  and  Bachman,  in  1842,  described  Spermophilus  {^Citel- 
lus) annulatus,  and  in  1854,  S.  harrisii — both  from  unknown  locali- 
ties— and  in  1855,  Baird  added  S.  couchii  from  northern  Mexico. 

Thus,  when  Baird's  monograph  appeared  in  1857,  there  had  been 
described  16  valid  races  of  ground  squirrels  from  North  America, 
and  of  these  all  but  three  were  treated  in  the  monograph.  Spermo- 
philus annulatus  was  thought  to  be  an  African  species  of  Sciurus;  S. 
macrourus  of  Bennett  {^Citelhis  variegatus)  was  provisionally  in- 
cluded, while  Ord's  Arctomys  columhianus  was  doubtfully  referred 
to  as  a  prairie  dog.  Baird  added  in  this  paper  one  new  species — the 
round-tailed  spermophile  of  the  Southwest — Spermophilus  tereti- 
caudus. 

In  1861,  Ross  named  a  form  of  Parry's  spermophile,  Arctomys 
Icennicottii  (not  now  recognized),  and  Slack  described  the  black  rock 
squirrel  of  Texas,  Spermophilus  hucMeyi.  Kennicott,  in  1863,  de- 
scribed four  new  forms,  all  of  which  are  now  recognized  as  valid: 
Spermophilus  mollis,  S.  armatus,  S.  elegans,  and  S.  obsoletus. 


56  NORTH  AMERICAN  FAUNA  [No.  56 

J.  A.  Allen  added  Speniiophilus  parryii  hodiacensis  in  1874  and  S. 
tridecemlineatus  paUidus  in  1877.  In  his  Monograph  of  the  Rodentia 
(1877)  17  forms  were  treated,  only  three  more  than  appeared  in 
Baird's  monograph  issued  20  years  earlier.  Spermophilus  townsendii 
was  considered  to  be  a  variety  of  Hchardsonii,  whereas  elegans  and 
armatus  were  both  listed  in  the  synonymy  of  that  species.  Parry's 
spermophile  appeared  under  the  name  of  S.  empetra,  while  S.  har- 
risii  and  S.  lateralis  were  transferred  to  the  genus  Tamias. 

No  more  new  species  were  described  until  1888,  when  Merriam 
named  Spermophilus  heldingL  Shortly  after  this,  the  modern  period 
of  activity  in  systematic  mammalogy  began,  initiated  largely  by  the 
extensive  researches  and  explorations  of  Merriam  and  his  collectors 
in  the  Biological  Survey.  At  the  beginning  of  this  period,  1889, 
30  forms  of  North  American  ground  squirrels  had  been  named,  of 
which  25  are  now  considered  valid  races.  Since  that  time,  91  addi- 
tional forms  have  been  named,  of  which  69  are  considered  valid ;  three 
new  races  are  named  in  the  present  paper,  making  a  total  of  97 
recognized  races. 

Key  to  Subgenera 

a\  Molars   relatively   hypsodont;    parastyle   ridge   on   m^   and   m^ 
joining  the  protocone  with  an   abrupt  change  of  direction. 

6\  Metaloph  on  pm*  continuous Citellus    (p.  59) 

6^  Metaloph  on  pm*  not  continuous Ictidomys   (p.  106) 

c^  Molars     relatively     braehydont :     parastyle     on     m*     and     m* 
rising  evenly  to  join  the  protocone,  without  abrupt  change 
of  direction. 
6\  Anterior  upper  premolar   simple ;   less   than   one-fourth  the 
size  of  pm*. 
c^.  Upper    incisors   relatively    stout   and   distinctly    recurved. 
<Z\  Brain  ease  rounded  on  upper  surface. 

e\  Supraorbital  foramen  open Otospermophilus  (p.  135) 

e^  Supraorbital  foramen  closed Notocitellus  (p.  162) 

d^.  Brain  case  flattened  on  upper  surface Ammospemiophilus  (p.  166) 

c".  Upper  incisors  relatively  slender,  not  distinctly  recurved. 
d\  Postorbital     processes     long     and      slender ;      rostrum 

longer CallospermopMlus   (p.  190) 

d"^.  Postorbital      processes      short      and      stout ;      rostrum 

shorter Xerospermophilus  (p.  183) 

&^  Anterior  upper  premolar  bearing  two  cusps  and  a  fimc- 
tional  cutting  edge ;  more  than  one-fourth  the  size 
of  pm* Poliocitellus  (p.  133) 

List  of  Species  and  Subspecies,  with  Type  Localities 
Subgenus  CITELLUS  Oken 

citellus  townsendii  gkoup 

Citellus  townsendii  townsendii  (Bachman) Columbia  River,  near  mouth  of 

Walla  Walla  River,  Washing- 
ton. 

townsendii  canus  (Merriam) Antelope,  Oregon. 

townsendii  vigilis  Merriam Vale,  Oregon. 

townsendii  mollis  (Kennicott) Camp     Floyd,     near     Fairfield, 

Utah. 

townsendii  artemesiae  Merriam Birch  Creek,  Idaho. 

idahoensis  (Merriam) Payette,  Idaho. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  57 


CITELLUS  WASHINGTONI  GROUP 

Citellus  washingtoni  washingtoni,  nobis Toucliet,  Washington. 

washingtoni  loringi,  nobis Douglas,  Washington. 

brunneus  Howell New  Meadows,  Idaho. 

CITELLUS  RICHARDSONII  GROUP 

Citellus  richardsonii  richardsonii  (Sabine) Carlton  House,  Saskatchewan. 

richardsonii  elegans  (Kennicott) Fort  Bridger,  Wyoming. 

richardsonii  nevadensis 'H.oviell Paradise,  Nevada. 

armatus  (Kennicott) Fort  Bridger,  Wyoming. 

beldingi  beldingi  (Merriam) Donner,  California. 

beldin'gi  oregonus  (Merriam) Swan  Lake  Valley,  Oregon. 

CITELLUS  PARRYII  GROUP 

Citellus  columbianus  columbianus  (Ord) Camas  prairie,  between  the  forks 

of  the  Clearwater  and  Koos- 
kooskie  Rivers,  Idaho. 

columbianus  ruficaudus  B.OTvel\ Wallowa  Lake,  Oregon. 

parryii  parryii  {Rich&Tdson) Lyon  Inlet,    Melville   Peninsula, 

Canada. 

■parryii  barrowensis  (Merriam) Point  Barrow,  Alaska. 

parryii  plesius  (Osgood) Bennett  City,  British  Columbia. 

parryii  ablusus  Osgood Nushagak,  Alaska. 

parryii  nebulicola  Osgood Nagai  Island,  Shumagin  Islands, 

Alaska. 

parryii  lyratus  Hall  and  Gilmore St.  Lawrence  Island,  Alaska. 

kodiacensis  (Allen) Kodiak  Island,  Alaska. 

osgoodi  (Merriam) Fort  Yukon,  Alaska. 

Subgenus  ICTIDOMYS  Allen 

CITELLUS  TRIDECEMLINEATUS  GROUP 

Citellus  tridecemlineatus  tridecemlineatus  (Mit- 

chill) Central  Minnesota. 

tridecemlineatus  texensis  (Merriam) Gainesville,  Texas. 

tridecemlineatus  arenicola  Howell Pendennis,  Kansas. 

tridecemlineatus  pallidus  (Allen) Yellowstone  River  (mouth),  Mon- 
tana. 

tridecemlineatus  alleni  (Merriam) Bighorn  Mountains,  Wyoming. 

tridecemlineatus  hollisteri  Bailey Sacramento   Mountains,   New 

Mexico. 

tridecemlineatus  monticola  Howell White  Mountains,  Arizona. 

tridecemlineatus  parvus  {Ml&u) Uncompahgre    Indian    Reserva- 
tion, Utah. 

mexicanus  mexicanus  (Erxleben) Toluca,  Mexico. 

mexicanus  parvidens  (Mearns) Fort  Clark,  Texas. 

CITELLUS  SPILOSOMA  GROUP 

Citellus  spilosoma  spilosoma  (Bennett) Durango,  Mexico. 

spilosoma  pallescens  Howell La  Ventura,  Coahuila. 

spilosoma  canescens  (ISIerriam) Willcox,  Arizona. 

spilosoma  major  (Merriam) Albuquerque,  New  Mexico. 

spilosoma  annectens  (Merriam) Padre  Island,  Texas. 

spilosoma  pratensis  iMeTTiam) San    Francisco    Mountain,    Ari- 
zona. 

spilosoma  cryptospilotus  (Merriam) Painted  Desert,  Arizona. 

spilosoma  obsoletus  (Kennicott) Western  Nebraska. 

perotensis  (Merriam) Perote,  Veracruz. 

Subgenus  POLIOCITELLUS,  nobis 

Citellus  franklinii  (Sabine) Carlton  House,  Saskatchewan. 


58  NORTH  AMERICAN  FAUNA  [No.  56 

Subgenus  OTOSPERMOPHILUS  Brandt 

Citellus  variegatus  variegatus  (Erxleben) Valley  of  Mexico,  Mexico. 

variegatus  rwpestris  Allen Rio  Sestin,  Durango. 

variegatus  couchii  (Baird) Santa  Catarina,  Nuevo  Leon. 

variegatus  buckleyi  (Slack) Packsaddle  Mountain,  Texas. 

variegatus  grammurus  (Say) Purgatory  River,  Colorado. 

variegatus  tularosae  "Qqhsovl Carrizozo,  New  Mexico  (12  mi. 

northwest) . 

variegatus  utah  Merriam Ogden,  Utah. 

beecheyi  beecheyi  (Richardson) San    Francisco     and    Monterey, 

California  (neighborhood  of). 

beecheyi  douglasii  (Richardson) Lower  Columbia  River,  Oregon, 

beecheyi  sierrae,  nobis Lake  Tahoe,  California. 

beecheyi  fisheri  (Merriam) Onyx,  California. 

beecheyi  parvulus  Howell Argus  Mountains,  California. 

beecheyi  nudipes  Huey Hanson  Laguna,  Baja  California. 

beecheyi  rwpinarum  Huey Catavina,  Baja  California. 

beecheyi  nesioticus  Elliot Catalina  Island,  California. 

atricapillus  (Bryant) Comondii,  Baja  California. 

Subgenus   NOTOCITELLUS,  nobis 

Citellus    annulatus    annulatus     (Audubon  and 

Bachman) Manzanillo,  Colima. 

annulatus  goldmani  (Merriam) Santiago,  Nayarit. 

adocetus  Merriam La  Salada,  Michoacan. 

Subgenus  AMMOSPERMOPHILUS  Merriam 

Citellus harrisiiharr isii(Auduhonand'Bsichin.a,ii).  Santa  Cruz  Valley,  Arizona. 

harrisii  saxicola  (Mearns) Tinajas  Altas,  Arizona. 

leucurus  leucurus  (Merriam) San  Gorgonio  Pass,  California. 

leucurus  tersus  (Goldman) Prospect  VaUey,  Grand  Canyon, 

Arizona. 

leucurus  cinnamomeus  (Merriam) Painted  Desert,  Arizona. 

leucurus  pennipes  (Howell) Grand  Junction,  Colorado. 

leucurus  peninsulae  (Allen) San  Telmo,  Baja  California. 

leucurus  canfieldae  (Huey) Punta  Prieta,  Baja  California. 

leucurus  extimus  (Nelson  and  Goldman)  __  Saccaton,  Baja  California. 

interpres  (Merriam) El  Paso,  Texas. 

insularis  (Nelson  and  Goldman) Espiritu  Santo  Island,  Baja  Cali- 
fornia. 
nelsoni  (Merriam) Tipton,  California. 

Subgenus  XEROSPERMOPHILUS  Merriam 

Citellus  mohavensis  (Merriam) Hesperia,  California  (15  mi.  east) . 

tereticaudus  tereticaudus  (Baird) Old  Fort  Yuma,  California. 

tereticaudus  neglectus  (Merriam) Dolan  Spring,  Arizona. 

tereticaudus  chlorus  Elliot Palm  Springs,  California. 

tereticaudus  apricus  Huey Trinidad  Valley,  Baja  California. 

Subgenus  CALLOSPERMOPHILUS  Merriam 

Citellus  lateralis  lateralis  (Say) Canon  City,  Colorado. 

lateralis  wortmani  (Allen) Bitter  Creek,  Wyoming. 

lateralis  arizonensis  (Bailey) San  Francisco  Mountain,  Ari- 
zona. 

lateralis  caryi  (Ro-'nqW) Wind  River  Mountains,  Wyo- 
ming. 

lateralis  cinerascens  (Merriam) Helena,  Montana. 

lateralis  tescorum  (Hollister) Smoky    River    (head),    Alberta. 

lateralis  castanurus  (Merriam) Park  City,  Utah. 

lateralis  chrysodeirus  (Merriam) Fort  Klamath,  Oregon. 

lateralis  connectens  (Howell) Homestead,  Oregon. 

lateralis  trepidus  (Taylor) Pine  Forest  Mountains,  Nevada. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  59 


CiteUvs  lateralis  cerius  (Goldman) Charleston  Peak,  Nevada. 

lateralis  bernardinus  (Merriam) San  Bernardino  Peak,  California. 

lateralis  mitraius  (Howell) South    Yolla    Bolij^     Mountain, 

California. 

lateralis  trinitatis  (Merriam) Trinity  Mountains,  Cahforuia. 

saiurafus  (Rhoads) Lake  Keechelus,    Washington. 

madrensis  (Merriam) Sierra  Madre,  Chihuahua. 

Explanation  of  Cranial,  Measueements 

Measurements  of  the  skulls  of  Citellus  have  been  taken  in  millimeters,  as 
follows : 

Qreatest  length. — From  anterior  border  of  nasals  to  posterior  border  of  supra- 
occipital  in  median  line. 

Palatilar  length. — From  posterior  border  of  upper  incisors  to  posterior  border 
of  palate  (disregarding  median  process). 

Zygomatic  breadth. — Greatest  breadth  across  zygomata. 

Cranial  breadth. — Least  breadth  of  cranium  measured  just  behind  the 
-zygomata. 

Interorbital  breadth. — Least  breadth  across  froutals  in  front  of  postorbital 
processes. 

Postorbital  constriction. — Least  breadth  across  frontals  behind  postorbital 
processes. 

Length  of  )iasals. — Greatest  length  of  nasals,  measured  along  median  line. 

Maxillary  tooth  row. — Alveolar  length  of  maxillary  molar-premolar  tooth  row. 

Subgenus  CITELLUS  Oken 

[For  subgeneric  cbaracters,  see  p.  40] 

Key  to  Species  and  Subspecies 

a\  Upper  parts  unspotted. 

6\  Hind  foot  more  than  39  mm. 

c\  Under  side  of  tail  grayish armatus  (p.  78) 

c^.  Under  side  of  tail  huffy  or  reddish. 
d\  Under  side  of  tail  huffy. 

e\  Upper  parts  more  buffy r'lchardsonii  (p.  73) 

€^.  Upper  parts  more  grayish elegans  (p.  76) 

ri^  Under  side  of  tail  reddish. 

e\  Upper  parts  mainly  reddish beldingi  (p.  81) 

e^  Upper  parts  mainly  grajdsh. 

f.  Under  side  of  tail  hazel ' oregonus  (p.  83) 

f.  Under  side  of  tail  sayal  brown nevadensis  (p.  77) 

6^  Hind  foot  less  than  39  mm. 

c^.  Size  large    (average  length   about  24(5  mm)  ;   upper  parts 

dappled iduhoensis  (p.  68) 

c*.  Size  smaller   (average  length  about  226  mm)  ;  upper  parts 
plain. 

d\  Size  smaller  (skull  length,  32.4-35.3) artemesiae  (p.  65) 

d-.  Size  larger  (skull  length,  34.6-39.6). 
e\  Upper  parts  mainly  grayish. 

f.  Tail  longer  (44-61  mm) mollis  (p.  63) 

f.  Tail  shorter  (37-42  mm) canus  (p.  67) 

e^.  Upper  parts  mainly  buffy. 

f.  Skull  larger  (37..3-39.6  mm)  ;  color  paler vigilis  (p.  66) 

f.  Skull  smaller  (37-38.7  mm)  ;  color  darker townsendii  (p.  60) 

o'.  Upper  parts  spotted  or  mottled. 

b^.  Size  larger  (hind  foot  more  than  40  mm). 
c\  Dorsal  spots  whitish. 

d^   Hind  feet  darker  (hazel) osgoodi  (p.  104) 


go  NORTH  AMERICAN  FAUNA  [No.  56 

al  Upper  parts  spotted  or  mottled — Continued. 

&\  Size  larger  (hind  foot  more  than  40  mm) — Continued. 
c\  Dorsal  spots  whitish — Continued. 

d"^.  Hind  feet  paler  (cinnamon,  buff,  or  clay  color). 

e\  Tail  shorter  (77-82  mm) nebuUcola  (p.  100) 

el  Tail  longer   (81-138  mm). 
f.  Dorsal  spots  smaller. 

g^.  Tail    darker    (more    blackish)     above,    paler    be- 
neath  kodiacensis   (p.  103) 

g^.  Tail  paler  above,  darker  beneath plesius  (p.  97) 

f.  Dorsal  spots  larger. 

g^.  Under  parts  darker  in  summer  pelage  (ochraceous 

tawny) parryii  (p.  91) 

g^.  Under  parts  paler  in  summer  pelage    (cinnamon 
bufe). 
h^.  Size  larger   (skull  length,  58-62.8  mm)_  larroivensis  (p.  95) 
h".  Size  smaller  (skull  length,  54-58.8  mm). 

t\  Upper  parts  brownish ailusus  (p.  98) 

f.  Upper  parts  grayish lyratus  (p.  101) 

(f.  Dorsal  spots  buffy. 

d\  Tail  mainly  grayish  above columbianus  (p.  85) 

d^.  Tail  mainly  reddish  above ruflcaudus  (p.  89) 

6l  Size  smaller  (hind  foot  less  than  40  mm), 
c^.  Upper  parts  grayish. 

d^.  Size  larger  (hind  foot,  34-38  mm) washingtoni  (p.  69) 

d\  Size  smaller   (hind  foot,  30-33  mm) loringi   (p.  71) 

cl  Upper  parts  brownish hrunneus  (p.  72) 

CITELLUS  TOWNSENDII  GROUP 

CITELLUS   TOWNSENDII    (Bachman) 

[Synonymy  under  subspecies] 

SpecifiG  characters. — Size  small;  hind  foot  29-36  mm;  tail  32-61; 
skull  length  32.'^39.6.  Skull  relatively  short  and  broad;  zygomata 
heavy  and  rather  widely  expanded;  rostrum  stout,  its  sides  nearly 
parallel ;  supraorbital  borders  slightly  elevated ;  postorbital  processes 
long,  slender,  decurved;  brain  case  broad;  temporal  ridges  lyrate, 
meeting  posteriorly  in  old  age  to  form  a  slight  crest ;  audital  bullae 
moderately  inflated,  the  meatus  rather  long;  molars  hypsodont;  upper 
incisors  rather  slender.  Coloration  plain,  smoke  gray,  shaded  with 
pinkish  buff  or  pinkish  cinnamon ;  tail  cinnamon  drab,  sayal  brown, 
or  clay  color. 

CITELLUS  TOWNSENDII   TOWNSENDII    (Bachman) 

TOWNSEND'S   GEOtrND   SQUIEEEIi 

Spernwphilus  townsendii  Bachman,  Jour.  Acad.  Nat.   Sci.  Phila.  8:  61,  1839; 

Townsend,  Narr.  Jour.  Rocky  Mountains  to  Columbia  River,  etc.,  p.  316,  1839. 
Spennophilus  mollis  yakimensis  Merriam,  Biol.  Soc.  Wash.  Proc.  12:  70,  Mar. 

24,  1898. 
[Gitellus  mollis]  yakimensis  Trouessart,  Cat.  Mamm.,  Sup.,  p.  339,  1904. 

Type. — Collected  "on  the  Columbia  River,  about  300  miles  above 
its  mouth"  [near  the  mouth  of  Walla  Walla  River,  Wash.],  in  July 
1836,  by  J.  K.  Townsend ;  mounted  specimen  no.  344,  collection  Acad. 
Nat.  Sci.  Philadelphia. 

Range. — South-central  Washington,  between  the  Columbia  River 
and  the  Cascade  Range,  north  to  EUensburg  (fig.  1).  Zonal  range: 
Upper  Sonoran. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


61 


External  characters. — Similar  in  color  to  G.  t.  canus  and  C.  f. 
vigilis  but  averaging  more  buffy  or  brownish  (less  grayish)  above; 
tail  and  hind  feet  longer  than  in  canus. 

Cranial  characters. — Skull  similar  to  that  of  canus  but  averaging 
longer  (actually  and  relatively),  with  decidedly  longer  nasals  and 
tooth  row,  and  larger  audital  bullae. 

Color. — Winter  felage  (March)  :  Upper  parts  smoke  gray,  shaded 
with  pinkish  buff;  patch  on  front  of  face  cinnamon;  sides  of  face 
and  head  smoke  gray;  sides  of  body  faintly  washed  with  pinkish 


FiGUUE   1.^ — Distribution   of   the  subspecies   of  Citellus    toicnsendii:  1.    C.   t.   totcnsendU; 
2,  C.  t.  canus;  3,  V.  t.  vigilis;  4,  C.  t.  artemesiae ;  5,  V.  t.  mollis. 

buff;  thighs  cinnamon;  feet  pinkish  buff;  tail  cinnamon  or  sayal 
brown,  shaded  with  fuscous  and  edged  with  buffy  Avhite  or  pinkish 
butt";  under  parts  creamy  white,  washed  with  pinkish  buff.  ^Vo7'n 
summer  pelage  (July  16)  :  Paler  and  more  grayish  than  in  winter 
and  not  appreciably  different  from  canus  at  that  season. 

Variation. — A  single  specimen  in  a  series  of  14  taken  in  ISIarch 
at  Ellensburg  and  Yakima  is  decidedly  darker  than  the  rest,  the 
upper  parts  being  uniform  pale  snuff'  brown. 

Measurements.'^ — Average  of  10  adults  from  Mabton  and  North  Yakima, 
Wash.:  Total  length,  212.2  (200-2:^2);  tail  vertebrae,  45.7  (39-54);  hind 
foot,  3.3.9  (32-37).  SkuU:  Average  of  10  adults  from  Mabton,  Bickleton,  and 
North  Yakima:  Greatest  length,  37.9  (37.1-38.7)  ;  palatilar  length,  17.9  (17.3- 
18.2)  ;    zygomatic   breadth,   24    (23.3-25.1)  ;    cranial   breadth    17.9    (17.-JH8.4)  ; 


•All  measurcmenta  are  in  millimeters   (see  p.  59). 


62  NORTH  AMERICAN  FAUNA  [No.  56 

interorbital    breadth,    7.5    (7-8.2)  ;    postorbital    constriction,    10.3     (9.4-10.9)  ; 
length  of  nasals,  14.5  (13.2-15.7)  ;  maxiUary  tooth  row,  8.2  (8-8.5). 

Remarks. — This  species,  although  first  recognized  nearly  100  years 
ago,  remained  imperfectly  known  for  most  of  that  period  and  at  the 
present  time  the  name  townsendii  is  currently  applied  to  another 
species  (here  described  under  the  name  Gitellus  washingtoni) .  The 
type  specimen  was  collected  by  J.  K.  Townsend,  "on  the  Columbia 
Kiver,  about  300  miles  above  its  mouth,  in  July"  1836  (Townsend, 
1839,  p.  316).  Bachman  (1839,  p.  61),  in  the  original  description, 
states  that  Townsend  informed  him  that  the  species  inhabits  "the 
prairies  near  the  Walla- walla."  It  so  happens  that  in  the  section 
alon^  the  Columbia  River  at  the  mouth  of  the  Walla  Walla  River  two 
species  of  ground  squirrels  occur — a  plain-colored  form  on  the  west 
side  of  the  river  and  a  spotted  species  on  the  east  side.  Townsend 
does  not  state  on  which  side  of  the  river  his  specimen  was  taken. 

Fortunately,  the  type  specimen  has  been  j)reserved  in  the  collection 
of  the  Academy  of  Natural  Sciences  of  Philadelphia  (no.  344),  and 
through  the  courtesy  of  the  authorities  of  that  institution  the  writer 
has  been  able  to  examine  and  compare  it  with  modern  specimens. 
The  type  specimen  had  been  mounted  with  the  skull  inside  and  in 
the  course  of  years  it  has  become  so  covered  with  grease  and  dirt  as 
to  be  almost  unrecognizable.  After  being  immersed  for  several  days 
in  petroleum  ether,  however,  the  grease  has  largely  been  removed 
and  the  animal  is  seen  to  lack  the  conspicuous  buffy  white  spots  of 
the  species  living  on  the  east  side  of  the  Columbia,  currently  known 
under  the  name  Gitellus  townsendii. 

A  brief  review  of  the  history  of  this  name  will  assist  in  clearing 
up  the  misunderstanding  as  to  its  allocation.  In  the  original  descrip- 
tion no  mention  is  made  of  dorsal  spotting,  but  in  Audubon  and 
Bachman  (1854,  p.  226)  the  description  of  this  species  includes  a 
statement  that  it  is  "speckled  with  white  all  over  the  back."  This, 
however,  apparently  does  not  mean  that  it  is  spotted,  for  on  page 
228  the  authors  say  that  they  compared  a  specimen  with  the  Euro- 
pean Spermophilus  guttatus — a  coarsely  spotted  species — and  found 
it  very  different.  "They  may  be  distinguished  from  each  other  at 
a  glance  by  the  large  rounded  spots  on  the  back  of  the  Russian  ani- 
mal, compared  with  the  white  and  irregular  specks  in  the  American 
species." 

J.  A.  Allen,  in  a  paper  listing  the  species  and  varieties  of  the  North 
American  Sciuridae  (1874,  p.  293),  correctly  associated  townsendii 
with  Spermophilus  mollis^  but  in  his  monograph  of  the  group  ( 1877, 
pp.  84&-854)  he  transferred  the  name  to  the  form  described  by  Ken- 
nicott  in  1863  as  S.  elegans^  listing  it  as  a  variety  of  S.  richardsoni. 

Merriam  (1891,  p.  36)  showed  that  Allen's  assignment  of  the  name 
to  elegans  was  wrong,  and  applied  it  to  the  small  unspotted  ground 
squirrel  of  southern  Idaho,  listing  S.  mollis  as  a  possible  subspecies 
of  the  same  group. 

Twenty-two  years  later  (1913,  p.  137)  Merriam  described  this 
Idaho  race  under  the  name  G.  mollis  artemesiae,  but  failed  to  asso- 
ciate it  with  townsendii,  as  he  had  previously  done. 

In  May  1891  a  collector  from  the  Biological  Survey  obtained  a 
series  of  the  spotted  ground  squirrels  from  Pasco  and  Touchet, 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  63 

Wash.,  and  on  the  assumption  that  they  came  from  the  type  region 
of  towThsendii,  they  were  referred  to  that  species  and  so  labeled  in 
the  Biological  Survey  collection.  Now,  however,  since  the  type  speci- 
men of  townsendii  proves  to  be  unsj)otted,  and  agrees  in  size  and 
general  coloration  with  the  species  living  on  the  west  side  of  the 
Columbia  River,  it  becomes  necessary  to  transfer  the  name  town- 
sendii to  that  race  now  known  as  Gitellus  mollis  yakimensis. 

This  race  is  apparently  isolated  by  the  Columbia  River  from  the 
other  races  of  townsendii;  it  is  most  nearly  related  to  canus  but  is 
decidedly  more  brownish,  especially  in  winter  pelage.  Contrary  to 
the  usual  condition  in  this  group  the  winter  pelage  is  more  brownish 
(less  grayish)  than  the  summer  pelage. 

/Specimens  examined. — Total  number,  33,  as  follows: 

Washington:  Bickleton,  3;  Columbia  River  Valley  (20  miles  south  of  Priest 
Rapids),  1;  EUensburg,  8;  Kiona  (Benton  County),  2;'  Mabton,  9;  North 
Yakima,  3 ;  Wiley  City,  6 ;  Yakima,  1.' 

CITELLUS  TOWNSENDII  MOLLIS  (Kennicott) 

Piute  Ground  Squirrel 

(Pis.  1;  23,  A;  28,  A) 

Spertnophilus  mollis  Kennicott,  Acad.  Nat.  Sci.  Phila.  Proc.  1863 :  157. 

[Spermophilus  townaendi]  var.  mollis  Allen,  Boston  Soc.  Nat.  Hist.  Proc.  16: 
293,  1874. 

Spermophilus  mollis  stephensi  Merriam,  Biol.  Soc.  Wash.  Proc.  12:  69,  1898. 
(Queen  Station,  near  head  of  Owens  Valley,  Nev.) 

[Citellusl  mollis  Trouessart,  Cat.  Mamm.,  Sup.,  p.  339,  1904. 

Citellus  leurodon  Merriam,  Biol.  Soc.  Wash.  Proc.  26:  136,  1913.  (Murphy, 
Idaho.) 

Citellus  mollis  washoensis  Merriam,  Biol.  Soc.  Wash.  Proc.  26:  138,  1913.  (Car- 
son Valley,  Nev.) 

Type. — Collected  at  Camp  Floyd,  near  Fairfield,  Utah,  March  18, 
1859,  by  C.  S.  McCarthy ;  skin  and  skull,  no.  ^^ ,  U.  S.  Natl.  Mus. 
(orig.  no.  164.) 

Range. — Western  Utah,  southern  Idaho,  Nevada,  and  southeastern 
Oregon;  north  to  Pocatello  and  Weiser,  Idaho,  and  Rome,  Oreg.; 
east  to  Salt  Lake  City  and  Manti,  Utah ;  south  to  Cedar  City,  Utah, 
and  Clark  County,  Nev. ;  west  to  Carson,  Nev.,  and  Honey  Lake  and 
Owens  Valley,  Calif,  (fig.  1).    Zonal  range:  Upper  Sonoran. 

External  characters. — Smaller  and  paler  than  G.  idahoensis;  color 
plain  smoke  gray,  without  distinct  dappling;  tail  paler  and  less 
bushy. 

Cranial  characters. — Skull  about  the  size  of  that  of  C.  washingtoni 
washingtoni;  in  comparison  with  that  of  the  other  races  of  C.  town- 
sendii., relatively  long  and  narrow,  the  zygomata  not  wide  spreading ; 
rostrum  and  nasals  long,  the  nasals  ending  posteriorly  on  a  line  with 
the  premaxillae  or  beyond  them. 

Color. — Gray  phase  (Fairfield,  Utah,  June  28)  :  Upper  parts  uni- 
form smoke  gray  (a  subterminal  band  of  snuif  brown  or  bister  on 
the  body  hairs,  in  worn  pelage,  lends  a  brownish  cast  to  the  general 
tone,  with  a  suggestion  of  "dappling") ;  nose  and  front  of  face  cin- 
namon or  clay  colDr;  sides  of  head  and  body  often  more  or  less 
washed  with  pinkish  buff;  eyelids  creamy  white  or  pinkish  buff; 

^  Univ.  Michigan  Mu8.  Zool. 


g4  NORTH  AMERICAN  FAUNA  [No.  56 

front  feet  pinkish  buff;  hind  feet  grayish  white,  sometimes  washed 
with  pinkish  cinnamon;  thighs  usually  strongly  washed  with  pink- 
ish cinnamon;  tail  above  and  below  smoke  gray,  strongly  shaded 
with  cinnamon  or  snuff  brown,  especially  on  distal  portion,  and 
edged  with  white;  under  parts  creamy  white,  washed  with  pinkisli 
buff.  Buff  phase:  Similar  to  the  gray  phase  biit  entire  upper  parts 
strongly  washed  with  pinkish  buff. 

Molt. — In  the  series  examined  there  is  no  clear  indication  of  when 
or  how  the  molt  takes  place ;  numerous  specimens  taken  in  the  latter 
half  of  May  and  early  in  June  are  in  badly  worn  pelage,  which 
would  indicate  that  the  molt  may  occur  in  June  or  July. 

Measurements. — Average  of  12  (ad.  and  subad.)  from  Fairfield,  Utah:  Total 
length,  213.1  (201-233)  ;  tail  vertebrae,  52  (4-^61)  ;  hind  foot,  33.7  (31-36). 
Skull:  Average  of  15  (ad.  and  subad.)  from  Fairfield,  Nephi,  Salt  Lake  City, 
and  Promontory,  Utah:  Greatest  length,  37.5  (36.1-39.3)  ;  palatilar  length,  18.2 
(17-19)  ;  zygomatic  breadth,  23.8  (22.7-25.7)  ;  cranial  breadth,  17.4  (16.4-18.5)  ; 
interorbital  breadth,  7.7  (6.5-8.5)  ;  postorbital  constriction,  10  (9.2-10.7)  ;  length 
of  nasals,  13.2  (12.6-14.4)  ;  maxillary  tooth  row,  8.2  (7.5-8.5). 

Weight. — Two  females  from  White  Horse  Sink,  Oreg.,  weighed  8  ounces  each. 

Remarks. — The  Piute  ground  squirrel  is  widely  distributed  in 
the  Great  Basin  and  has  been  known  for  many  years.  In  southeast- 
ern Idaho  it  grades  into  the  smaller  race  G.  t.  artemesic.e.  A  single 
specimen  from  Disaster  Peak,  Oreg.,  agrees  with  mollis  in  color  but 
in  skull  characters  resembles  C.  t.  canus. 

A  considerable  series  from  southern  Nevada,  including  topotypes 
of  the  form  ''''stephensi''\  prove  to  be  not  appreciably  different  from 
typical  mollis. 

The  form  described  from  Murphy,  Idaho,  under  the  name 
Heurodon'''  seems  clearly  referable  to  typical  mollis;  the  skull  of 
the  type  may  be  closely  matched  by  specimens  from  Utah,  and  the 
average  skull  measurements  of  a  series  of  Heurodon'''  show  no  im- 
portant differences  by  which  they  could  be  separated  from  mollis. 

The  form  described  from  Carson  Valley,  Nev.,  as  ^hvashoensis"  is 
slightly  darker  than  typical  mollis;  the  skull  of  the  type  is  from  a 
very  old  and  abnormally  large  individual,  but  that  of  another  adult 
male  in  the  series  is  closely  matched  by  specimens  of  mollis  from 
Salt  Lake  City,  Utah;  therefore,  ^^ivashoeiisis^^  is  placed  in  the  syn- 
onymy of  mollis.  Specimens  from  Pyramid  Lake,  Wadsworth,  Still- 
water, and  Smoke  Creek  are  typical  of  mollis. 

Specimens  examined. — Total  number,  249,  as  follows : 

California:  Amedee,  1 ;'  Honey  Lake,  3 ;*  Horse  Lake  (Lassen  County),  1 ;  Karlo 
(Lassen  County),  l;VLong  Valley  (Mono  County),  2;  Mono  Lake,  2;' 
Owens  Valley,  6;  Wendel  (Lassen  County),  2.* 

Idaho:  American  Falls,  6;  Gooding,  1;^  Murphy,  7;  Oakley,  1;  Payette,  1; 
Pocatello  10:  Rogerson,  1;  Rupert,  1;*  Weiser,  7. 

Nevada:  Baker  (White  Pine  County),  3;'  Blair  Junction  (Esmeralda  County), 
1;'  Carlin,  1:°  Carson,  13;  Cave  Spring  (Esmeralda  County),  1;^  Chiato- 
vich  Ranch  (Esmeralda  County),  1;*  Cloverdale  (Nye  Countv),  1;  Elko,  3; 
Fish  Lake  Valley  (Esmeralda  County),  3;'  Goldfield,  1;'  Goshute  Moun- 
tains, 1 ;  Granite  Creek  (Washoe  County) ,  1 ;  Halleck,  6 :  Indian  Creek  (near 
head,  Nye  County),  2;  Indian  Spring  (north  slope  Charleston  Mountains), 
1;"  Little  High  Rock  Canyon  (Washoe  County),  1;'  Metropolis,  2;  Millett 
(Nye  County),  1;*  Monitor  Valley  (50  miles  north  of  Belmont),  1;  Mount 
Magruder    (  =  Sugarloaf   Peak,   Esmeralda   County),   15;   Nixon    (Washoe 

sMus.  Vert.  Zool. 

^  Univ.  Michigan  Mus.  Zool. 

10  D.  R.  Dickey  coll. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  g5 

County),  1;  Osceola  (White  Pine  County),  1;'  Palmetto  (Esmeralda 
County),  5;**  Panaca  (Lincoln  County),  1;*  Paradise,  1;  Peavine  Creek 
(Nye  County),  4;  Pine  Forest  Mountains  (Big  Creek  Ranch),  4;'  Pyramid 
Lake,  20;  Queen  (Mineral  County),  6;  Quinn  River  Crossing  (Humboldt 
County),  17;'  Reese  River  (Nye  County),  4;  Round  Mountain  (Nye 
County),  3;  Steptoe  Valley  (9  miles  south  of  Schellbourne),  1;*  Silver  Peak 
Mountains,  1;  Smoke  Creek  (Washoe  County),  6;  Springdale  (Nye  County), 
4;^"  Stillwater  (Churchill  County),  1;  Summit  (Esmeralda  County),  1;'° 
Toyabe  Range,  2;  Virginia  Mountains  (Washoe  Coimty),  1;  Wadsworth,  3; 
White  River  Valley  (15  miles  southwest  of  Sunnyside),  1;'  Whiterock 
Valley  (30  miles  southwest  of  Austin),  1;  Winnemucca,  1;  Winnemucca 
Lake,  1. 

Oregon:  Disaster  Peal<:  (Malheur  County),  1;  Rome  (Malheur  County),  2; 
White  Horse  Sink  (Harney  County),  about  16  miles  east  of  Alvord  Lake,  2. 

Utah:  Cedar  City,  9;"*=*  Fairfield,  16;  Kelton  (Box  Elder  Coimty),  1;'  Malone 
(Millard  County),  1;  Manti,  1;  Midvale,  1;  Modena  (Iron  County),  4; 
Nephi,  1 ;  Promontory  (Box  Elder  County),  4 ;  Salt  Lake  City,  3. 

CITELLUS  TOWNSENDII  ARTEMESIAE  Mekbiam 

LELiST  Idaho  Ground  Squtrkei. 

Spennophilus   townsendi  Merriam,   North   Amer.   Fauna   5:  36,   1891    (not   of 

Bachman). 
Gitelliis  mollis  artemesiae  Merriam,  Biol.  Soc.  Wash.  Proc.  26:  137,  May  21,  1913. 
Citellus  mollus   [sic]   pessimus  Merriam,  Biol.  Soc.  Wash.  Proc.  26:  138,  1913 

(Big  Lost  River,  Idaho). 

Type. — Collected  on  Birch  Creek,  about  10  miles  south  of  Nicholia, 
Idaho,  August  9,  1890,  by  Vernon  Bailey;  male  adult,  skin  and  skull, 
1^0-  wtItj  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig. 
no.  1573). 

Range. — Southeastern  Idaho,  from  southern  Lemhi  County  south 
to  the  Snake  River  valley  (fig.  1).    Zonal  range:  Upper  Sonoran. 

External  characters. — Smallest  of  the  races  of  0.  toionsendii;  color 
slightly  darker  and  more  dappled  than  in  C.  t.  mollis.,  tinged  with 
brownish,  and  with  less  buff  on  sides  of  head  and  body. 

Cranial  characters. — Skull  decidedly  smaller  than  that  of  mollis., 
with  relatively  shorter  rostrum. 

Color. — Summer  pelage  (August)  :  Upper  parts  pale  smoke  gray, 
sometimes  faintly  washed  with  pinkish  cinnamon ;  nose  and  front  of 
face  cinnamon ;  sides  of  neck  and  body  only- faintly  tinged  M'ith  pink- 
ish buff;  front  feet  grayish  white,  washed  with  pinkish  buff;  hind 
feet  grayish  white;  thighs  cinnamon  buff;  tail  above,  cinnamon  buff 
rnixed  with  fuscous  and  with  a  subterminal  patch  of  fuscous  black, 
tipped  with  grayish  white;  tail  beneath,  dull  clay  color  or  cinnamon; 
under  parts  creamy  white,  faintly  washed  with  pinkish  buff. 

Measurements. — Average  of  7  adults  from  type  locality:  Total  length,  179 
(167-188)  ;  tail  vertebrae,  36.6  (32-43)  ;  hind  foot,  29.7  (2<>-31).  Skull:  Aver- 
ago  of  7  adults  from  typo  locality:  Greatest  length,  33.5  (32.4-35.3)  ;  palatilar 
length,  16  (15.3-16.8)  ;  zygomatic  breadth.  21.5  (21-23)  ;  cranial  breadth,  16.3 
(15.6-17.1)  ;  interorbital  breadth,  6.7  (6.4-7)  ;  po.storbital  constriction,  9.8  (9.2- 
10.3)  ;  length  of  nasals,  12  (11.4-12.7)  ;  maxillary  tooth  row,  7.4. 

Remarks. — This  small  race  of  townsendii  occupies  a  rather  limited 
area  in  southeastern  Idaho.  The  series  from  Big  Lost  River,  which 
forms  the  basis  of  Merriam's  ^^pessiinus^^  is  intermediate  in  size  between 

^•Mu.'i.   Vert.  Zool. 
»»D.  R.  Dickey  coll. 
»E.   R.  Warren  coll. 
12  Cleveland  Mus.  Nat.  Hist. 
1.54970—38 5 


gg  NORTH  AMERICAN  FAUNA  tNo.  56 

mollis  and  arteinesiae  but  nearer  to  the  latter.  _  The  specimens  appear 
slightly  darker  than  typical  artemesme  but  this  may  be  due  to  wear, 
and  in  any  case  the  difference  is  too  slight  to  warrant  recognition  of 
the  form  by  name. 
Specimens  examined. — Total  number,  31,  as  follows : 

Idaho:  Berenice  (Butte  County),  2;"  Big  Lost  River,  10;  Birch  Creek,  7; 
Blackfoot,  7;  Pingree  (Bingham  County),  2;"  Taber  (Bingham  County), 
2;"  Twin  Lakes,  Snake  River  Desert  (20  miles  north  of  Minidoka),  1. 

CITELLUS  TOWNSENDII  VIGILIS  Meekiam 

Malhetjb  Valley  Gbottnd  Sqtjireel 

Citellus  canus  vi gilts  Merriam,  BioL  Soc.  Wash.  Proe.  26 :  137,  May  21,  1913. 

Gitellus  mollis  vigilis  Miller,  U.  S.  Natl.  Mus.  Bull.  128  :  188, 1924. 

r^/^e.— Collected  at  Vale,  Oreg.  April  29,  1910,  by  Stanley  G. 
Jewett;  female  adult,  skin  and  skull,  no.  168361,  U.  S.  Natl.  Mus., 
(Biological  Survey  collection)  (orig.  no.  30). 

Range. — Confined  apparently  to  the  lower  part  of  Malheur  Valley, 
Oreg.,  in  the  vicinity  of  Vale  and  Ontario  and  north  in  the  Snake 
Eiver  valley  to  Huntington.    Zonal  range:  Upper  Sonoran. 

External  characters. — Largest  of  the  races  of  G.  townsendii;  closely 
similar  in  coloration  to  G.  t.  canus.,  but  averaging  slightly  more  buffy ; 
darker  (more  buffy)  than  G.  t.  mollis. 

Granial  characters. — Slmll  similar  to  that  of  canus.,  but  larger; 
averaging  about  the  same  length  as  that  of  mollis.,  but  zygomata 
heavier  and  more  widely  spreading;  rostrum  relatively  shorter  and 
broader ;  maxillary  tooth  row  slightly  shorter. 

Golor. — Worn  tvinter  pelage  (April  and  May)  :  Upper  parts  smoke 
gray,  sometimes  faintly  washed  with  pinkish  cinnamon ;  front  of  face 
with  a  rather  extensive  patch  of  cinnamon;  sides  of  neck  and  body 
faintly  (rarely  strongly)  washed  with  pinkish  buff  or  pale  pinkish 
buff ;  front  feet  pinkish  buff,  hind  feet  creamy  white ;  tail  above  and 
below,  cinnamon  drab,  mixed  with  fuscous,  edged  with  white  or  buffy 
white,  and  with  a  subterminal  patch  of  fuscous ;  under  parts  creamy 
white,  faintly  washed  with  pinkish  buff,  the  hairs  fuscous  at  base, 
and  this  color  often  more  or  less  prominent  in  mixture  with  the  lighter 
tips.    Summer  pelage :  Not  represented. 

Measurements. — Average  of  10  adults  from  Ontario  and  Vale,  Oreg. :  Total 
length,  226.2  (201-238)  ;  tail  vertebrae,  44.4  (35-52)  ;  hind  foot,  33.1  (31-35). 
Skull:  Average  of  13  adults  from  same  localities:  Greatest  length,  38.3  (37.S- 
39.6)  ;  palatilar  length,  18.4  (17.5-19.5)  ;  zygomatic  breadth,  25.5  (24.5-26.7)  ; 
cranial  breadth,  17.8  (17.2-18.4) ;  interorbital  breadth,  7.9  (7.3-8.4)  ;  postorbital 
constriction,  9.6  (8.9-10.5)  ;  length  of  nasals,  13.4  (12.8-13.8)  ;  maxillary  tooth 
row,  7.7  (7.2-8.2). 

Remarks. — ^Living  in  a  rich,  fertile  valley  this  race  has  developed 
markedly  in  size  and  robustness  of  skull.  Its  range  apparently  is 
quite  limited,  since  the  specimens  a  few  miles  to  the  westward  of 
Vale  are  referable  to  canus  and  those  on  the  east  side  of  Snake  River 
to  mollis. 

Specimens  examined. — Total  number,  53,  as  follows : 

Oregon :  Huntington,  4 ;  Ontario,  23 ;  Vale,  26. 


13  Mus.  Vert.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  67 

CITELLUS  TOWNSENDII  CANUS    (Merriam) 

Gray  Ground  Squikkel 

Spermophilus  mollis  canus  Merriam,  Biol.  Soc.  Wash.  Proc.  12 :  70,  Mar,  24, 1898. 
[Citellus  mollis]  canus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  339,  1904. 

Type. — Collected  at  Antelope,  Wasco  Comity,  Oreg.,  June  21,  1896, 
by  Vern6n  Bailey ;  female  adult,  skin  and  skull ;  no.  78681,  U.  S.  Natl. 
Mus.  (Biological  Survey  collection)  (orig.  no.  5561). 

Range. — Eastern  Oregon  and  extreme  northwestern  Nevada ;  north 
to  Antelope;  west  to  Warmspring,  Bend,  and  Summer  Lake;  south 
to  Summit  Lake,  Nev. ;  east  to  Catlow  Valley  and  Cedar  Mountains, 
Oreg.  (fig.  1).    Zonal  range:  Upper  Sonoran. 

External  characters. — Closely  similar  in  color  to  C.  t.  mollis;  tail 
and  hind  feet  shorter.  Similar  also  to  G.  t.  vigilis  but  smaller; 
cimiamon  patch  on  face  paler. 

Cranial  characters. — Skull  similar  in  shape  to  that  of  vigilis  but 
smaller.  Compared  with  mollis :  Shorter  and  relatively  broader,  the 
zygomata  more  wide  spreading;  bullae  averaging  smaller;  rostrum 
relatively  short  and  broad. 

Color. — Summer  pelage  (June  20-July  14)  :  Upper  parts  smoke 
gray,  often  with  a  faint  wash  of  pinkish  cinnamon  and  frequently 
more  or  less  darkened  by  exposure  of  the  subterminal  fuscous  areas 
of  the  hairs ;  patch  on  front  of  face  pinkish  cimiamon ;  sides  of  face, 
neck,  and  body  sometimes  faintly  shaded  with  pinkish  buff;  tail  and 
feet  as  in  vigilis.  Worn  lointer  pelage:  Practically  as  in  summer. 
Immature  pelage:  Similar  to  the  adult  pelage  but  often  strongly 
shaded  on  sides  of  head  and  body  with  pinkish  buff  or  cinnamon 
buff. 

Measurements. — Average?  of  10  adults  from  Antelope,  Gateway,  and  Prineville, 
Oreg.:  Total  length,  201.4  (190-217);  tail  vertebrae,  39.4  (37-42);  hind  foot, 
30.7  (29-33).  Skull:  Average  of  10  adults  from  Antelope  and  Gateway:  Great- 
est length,  36.3  (34.6-38)  ;  palatilar  length,  17.3  (16.5-18.5)  ;  zygomatic  breadth, 
23.9  (23.1-24.5)  ;  cranial  breadth.  17.(5  (17-18.2)  ;  interorbital  breadth,  7.5  (7-8)  ; 
postorbital  constriction,  10.1  (9.3-11)  ;  length  of  nasals,  12.9  (12.2-13.6)  ;  maxil- 
lary tooth  row,  7.4  (7-7.8). 

Remarks. — This  small  gray  race  occupies  most  of  the  desert  valleys 
of  eastern  Oregon  except  the  extreme  southeastern  part,  intergrading 
with  the  larger  vigilis  in  the  extreme  eastern  part  of  the  State  and 
with  mollis  in  southern  Malheur  County  and  in  northwestern  Nevada. 
There  are  no  records  of  its  occurrence  in  northern  Oregon,  north  of 
Antelope. 

Specimens  examined. — Total  number,  97,  as  follows : 

Nevada:  Hot  Springs,  Thousand  Creek,  3;"  Summit  Lake  (Humboldt  County), 
1;  Virgin  Valley  (Humboldt  County),  3." 

Oregon:  Antelope  (7  miles  east),  7;  Baker  (10  miles  north),  3;  ^'  Barnes  (Cook 
County),  1;"  Bend,  11;  Burns,  2;  Cedar  Mountains  (Malheur  County),  1; 
Christmas  Lake  (10  miles  north),  1;  Crane  (Harney  County),  6;  Drewsey, 
2;  Fremont,  1;  Gateway  (Jefferson  County),  15;  Haycreek  (Jefferson 
County),  5;  Malheur  Lake,  1;  Narrows,  17;  Plush  (Lake  County),  1;  Prine- 
ville. 6;  Riverside  (Malheur  County),  1;  Rock  Creek  (Harney  County),  4; 
Summer  Lake,  2;  Warmspring  (Jefferson  County),  3. 


"Mus.  Vert.  Zool. 

1"  Univ.  Michigan  Mus.  Zool. 


68 


NORTH  AMERICAN  FAUNA 


[No.  56 


CITELLUS  IDAHOENSIS  Mekeiam 

Snake  Valley  Ground  Sqxjieeel 

(Pls.  23,  B;  28,  B) 

Citellus  idahoensis  Merriam,  Biol.  Soc.  Wash.  Proc.  26 :  135,  May  21,  1913. 

Type.— Collected  at  Payette,  Idaho,  April  23,  1910,  by  Stanley  G. 
Jewett;  female  adult,  skin  and  skull,  no.  168290,  U.  S.  Natl.  Mus. 
(Biological  Survey  collection)   (orig.  no.  IT). 

Range. — North  side  of  Snake  River  Valley,  Idaho,  from  Payette 
to  Glenns  Ferry  (fig.  2).     Zonal  range:  Upper  Sonoran. 

External  charac- 
ters.— Similar  to  C. 
townsendii  mollis  but 
larger ;  tail  longer, 
and  more  tawny;  up- 
per parts  slightly 
darker  and  more  dis- 
tinctlj'^  dappled.  Com- 
pared with  C.  richard- 
sonii  elegans:  Size 
smaller ;  tail  shorter 
and  darker ;  coloration 
more  grayish  (less 
brownish  or  buffy). 

Cranial  charac- 
ters.— Skull  similar  to 
that  of  G.  tow-nsendii 
vigilis,  but  averaging 
larger ;  nasals  and 
molariform  tooth  row 
longer ;  similar  also  to 
that  of  mollis  but  de- 
cidedly larger;  audi- 
tory meatus  longer. 

Color. — U  nworn 
lointer pelage  (April)  : 
Upper  parts  pale 
smoke  gray,  faintly  or 
moderately  shaded 
with  pinkish  buff  or 
cinnamon  buff,  with  a 
slight  indication  of 
mottling ;  a  basal  zone  of  deep  mouse  gray  on  the  back,  succeeded  by 
a  zone  of  smoke  gray  and  then  by  a  subterminal  band  of  fuscous. 
Patch  on  front  of  face  sayal  brown;  sides  of  body  faintly  washed 
with  pinkish  buff;  front  feet  pinkish  buff;  hind  feet  buffy  whitish; 
tail  above,  mixed  pinkish  cinnamon  and  fuscous  edged  with  bufl'y 
white  and  with  a  subterminal  band  of  fuscous ;  tail  beneath,  cinnamon 
or  sayal  brown ;  under  parts  grayish  white,  faintly  washed  with  pinlc- 
ish  buff,  the  bases  of  the  hairs  fuscous.  Worn  winter  pelage  (June 
4)  :  General  tone  of  upper  parts  pale  snuff  brown  sprinkled  with 
pinkish  buff  (the  brownish  tones  due  largely  to  exposure  of  the 
subterminal  bands  on  the  hairs). 


Figure  2. — ^Distribution  of  Citellus  idahoensis. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  gQ 

Measurements. — Average  of  20  adults  from  Payette  and  Nampa,  Idaho: 
Total  length,  245.9  (222-271)  ;  tail  vertebrae,  59.2  (46-72)  ;  hind  foot.  35.6 
(33-38).  Skull:  Average  of  16  adults  from  same  localities:  Greatest  length, 
40.1  (37.7-43.3)  ;  palatilar  length,  19.4  (18-21.2)  ;  zygomatic  breadth,  25.9 
(25-26.8)  ;  cranial  breadth,  18  (17-19)  ;  interorbital  breadth,  8.2  (7.3-8.8)  ; 
postorbital  constriction,  9.7  (9-10.5)  ;  length  of  nasals,  14.3  (13.6-15.2)  ; 
maxillary  tooth  row,  8.3  (7.8-9). 

Remarks. — G.  idahoensis.,  although  evidently  belonging  in  the 
townsendii  group,  is  clearly  a  distinct  species,  since  it  occurs  in  certain 
areas  with  C.  t.  mollis  and  maintains  its  characters  without  inter- 
gradation.  It  is  best  distinguished  from  C.  t.  mollis  or  0.  t.  mgilis 
by  its  longer,  broader,  and  more  tawny  tail,  and  by  the  more  pro- 
nounced mottled  effect  on  the  upper  parts.  The  skulls  show  ex- 
treme variation  in  size,  and  the  smallest  ones  are  scarcely  distin- 
guishable from  those  of  vigilis,  though  usually  having  a  longer  and 
heavier  molar  tooth  row.  So  far  as  known,  the  species  occupies  a 
rather  restricted  range  on  the  north  side  of  the  Snake  River  Valley 
in  western  Idaho. 

S'pecim.ens  examined. — Total  nimiber,  118,  as  follows: 

Idaho:  Glenns  Ferry,  3;  Kuna   (Ada  County),  7;  Mountain  Home,  9;  Nampa, 
67;  Orchard  (Ada  County),  6;  Payette,  26. 

CITELLUS  WASHINGTONI  GROUP 

CITELLUS  WASHINGTONI,  SP.  Nov. 

[Synonymy  under  subspecies.] 

General  characters. — About  the  size  of  C.  toionsendii  mollis^'  hind 
foot,  30-38  mm ;  tail,  32-65 ;  skull  length,  35-41.4.  Skull  similar  to 
that  of  C.  t.  toionsendii  but  relatively  longer  and  narrower;  smaller 
and  relatively  narrower  than  those  of  G.  idahoensis  and  G.  hrunneus. 
Upper  parts  smoke  gray,  flecked  with  whitish  spots;  tail  mixed 
fuscous  and  grayish  white,  with  blackish  tip. 

CITELLUS  WASHINGTONI  WASHINGTONI,   subsp.   nov. 

Washington  Ground  SQxnBREi. 

(Pis.  1 ;  23,  C;  28,  C) 

Citellus   townsendii  Dice,   Jour.   Mammal.   1 :   18,   1919 ;    Bailey,   North   Amer. 
Fauna  55:  151,  1936  (not  Spermophilus  townsendii  Bachman). 

Type. — Collected  at  Touchet,  Walla  Walla  County,  Wash.,  May  18, 
1891,  by  Clark  P.  Streator;  male  adult,  skin  and  skull;  no.  |-^-|4, 
U.  S.  Natl.  Mus.  (Biological  Survey  collection^  (orig.  no.  817). 

Range. — Southeastern  Washington  and  nortliern  Oregon;  north  to 
southern  Adams  County,  Wash. ;  east  at  least  to  the  Idaho- Washing- 
ton boundary;  south  to  Heppner,  Oreg. ;  west  to  Willows,  Oreg. 
(fig.  3).    Zonal  range:  Upper  Sonoran. 

External  characters. — Size  medium;  tail  short;  dorsal  area  dis- 
tinctly spotted,  general  tone  grayish. 

Granial  characters. — Skull  similar  to  that  of  G.  idahoensis  but 
averaging  smaller,  and  relatively  narrower ;  interorbital  constriction 
narrower;  postorbital  processes  narrower  at  base  and  very  slender 
throughout ;  ascending  arms  of  premaxillae  narrower  than  the  nasals 
(about  equal  in  idahoensis)  ;  auditory  meatus  much  shorter.    Com- 


70 


NORTH  AMERICAN  FAUNA 


[No.  56 


pared  with  G.  townsendii  townsendii:  Skull  averaging  larger,  with 
relatively  narrower  brain  case  and  interorbital  region. 

Color. — Winter  pelage  (March)  :  General  tone  of  upper  parts  pale 
smoke  gray,  faintly  washed  (except  on  head)  with  pinkish  buff,  the 
entire  back  flecked  with  squarish,  grayish  white  spots  averaging 
about  3  or  4  mm  in  breadth;  patch  on  nose  and  front  of  face 
cinnamon;  eyes  surrounded  with  a  narrow  wliitish  ring;  sides  of 
body  very  faintly  washed  with  pale  buff;  feet  whitish,  tinged  with 
pinkish  buff,  thighs  pinkish  cimiamon;  tail  above,  grayish  mixed 
with  fuscous,  with  a  subterminal  band  of  fuscous  black,  tipped  with 
buffy  white;  tail  beneath,  pinkish  cimiamon  sometimes  mixed  with 
fuscous  and  edged  with  buffy  white;  under  parts  grayish  white, 
washed  with  pinkish  buff,  the  bases  of  the  hairs  fuscous.  Summer 
pelage   (August)  :  Upper  parts  more  brownish  or  fuscous  than  in 

winter,  due  appar- 
ently to  wearing 
away  of  the  whitish 
or  buffy  tips  on  the 
hairs  and  exposure 
of  the  subterminal 
brownish  areas. 

Molt. — Numerous 
specimens  taken  in 
May  and  June  are  in 
badly  worn  pelage, 
but  no  clear  indica- 
tions of  the  molt 
have  been  found  in 
the  series  examined; 
probably,  as  in  the 
case  of  other  species, 
the  pelage  is  renewed 
during  the  early  part 
of  sunnner. 

Measuretnents. — Average  of  15  adults  from  Wallula,  Pasco,  and  Toueliet, 
Wash. :  Total  length,  229.2  (212-245)  ;  tail  vertebrae,  50  (40-65)  ;  hind  foot, 
35.3  (34-38).  Skull:  Average  of  16  adults  (5  males,  11  females)  from  same 
localities:  Greatest  length,  38.5  (36.8-41.4);  palatilar  length,  18.3  (17-20); 
zygomatic  breadth,  24.8  (23.3-26.2)  ;  cranial  breadth  17.2  (16.3-18.3)  ;  inter- 
orbital breadth,  7.4  (6.6-8.2)  ;  postorbital  constriction,  9.2  (8-10.3)  ;  length  of 
nasals,  13.8  (13-15.6)  ;  maxillary  tooth  row,  7.8  (7.3-8.3).  Oregon  specimens 
average  larger  than  those  from  the  type  region ;  average  of  10  adult  males  from 
Pendleton  and  Willows:  Greatest  length,  39.4  (38.5-41.8)  ;  zygomatic  breadth,  26 
(24.8-27.5)  ;  cranial  breadth,  18.1  (16.8-18.7). 

Weight. — Shaw  (19251,  p.  764)  gives  the  weight  of  a  male  at  time  of  enter- 
ing hibernation  as  280  g ;  on  av/akening  at  the  end  of  a  period  of  56  days  the 
same  animal  weighed  221  g. 

Remarks. — This  ground  squirrel  has  been  known  for  nearly  half  a 
century  under  the  name  Citdlus  townsendii,  but  as  shown  on  page  62, 
that  name  is  applicable  to  another  species.  Therefore  it  has  become 
necessary  to  provide  a  name  for  the  species  under  consideration. 

The  Washington  ground  squirrel  is  easily  recognized  among  the 
American  forms  by  its  relatively  short  tail  and  conspicuous  dorsal 
spotting.  It  is  spotted  much  as  in  certain  forms  of  G.  spilosoma, 
but  the  latter  have  longer  tails,  harsher  pelage,  and  differ  widely  in 


Figure  3. — Distribution  of  Citellus  brunneus  and  sub- 
species of  C.  icashinytoni:  1,  C.  w.  loringi ;  2,  G.  iv. 
ivashingtoni;  3,  C.  brunneus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  71 

skull  characters.  The  present  form  resembles  G.  guttatus  of  south- 
ern Russia  rather  closely  in  general  appearance,  but  the  available 
material  does  not  permit  of  detailed  comparison.  There  is,  of  course, 
no  chance  of  close  relationship  between  the  two. 

The  nearest  relative  of  C.  washingtoni  is  C.  hrunneus  of  west- 
central  Idaho,  originally  described  by  the  writer  as  a  subspecies  of 
townsendii\^  =  washing toni]^  but  now  believed  to  be  a  distinct  species. 

The  range  of  this  species  is  separated  from  that  of  G.  townsendii 
townsendiihj  the  Columbia  River;  in  northern  Oregon,  luashingtoni 
occupies  an  area  west  of  the  Blue  Mountains  and  east  of  John  Day 
River,  while  G.  tovnsendii  canus  occupies  most  of  the  semidesert 
regions  of  the  State  to  the  southward.  The  ranges  of  washingtoni 
and  townsendii  apparently  do  not  overlap. 

Specimens  examined. — Total  number,  112,  as  follows : 

Oregon:  Cold  Springs  (Umatilla  County),  1;  Heppner,  9;  Pendleton,  17;  Pilot 
Rock  (Umatilla  County),  3;  Umatilla,  1;  Vinson  (Umatilla  County),  2; 
Willows  (Gilliam  County),  6;  Willows  Junction,  1. 

Washington:  Almota  (Whitman  County),  4;  Columbia  River,  1;"  Riparia 
(Whitman  County),  1;  Othello  (Adams  County),  1;"  Pasco,  19;  Pataha 
(Columbia  County),  S;"  Touchet,  27;  Wallula,  8;"  Wawawai,  2." 

CITELLUS  WASHINGTONI  LORINGI,   suESp.   nov. 

Loeing's  Ground  Squirrel 

Type. — Collected  at  Douglas,  Wash.,  August  1,  1897,  by  J.  Alden 
Loring;  male  adult,  skin  and  skull;  no.  89805,  U.  S.  Natl.  Mus.  (Bio- 
logical Survey  collection)   (orig.  no.  4547). 

Range. — Plains  of  east-central  Washington,  south  and  east  of  the 
Columbia  River,  including  most  of  Douglas,  Grant,  Lincoln,  and 
Adams  Counties;  east  to  Spokane  County  (fig.  3).  Zonal  range: 
Upper  Sonoran. 

Gharacters. — Similar  in  color  and  cranial  characters  to  G.  w.  wash- 
ingtoni but  smaller. 

Measurements. — Average  of  10  adult  males  from  type  region  (Douglas, 
Waterville,  Baird,  Farmer,  Coulee  Citv)  :  Total  length,  203  (185-224)  ;  tail 
vertebrae,  39.6  (32-48);  hind  foot,  30.8  (30-33).  Skull:  Average  of  10 
adult  males  from  same  localities:  Greatest  length,  36.4  (35-38);  palatilar 
length,  17.5  (17-18)  ;  zygomatic  breadth,  23.4  (22.6-24.5)  ;  cranial  breadth, 
17.2  (16.4-18)  ;  interorbital  breadth,  7  (6.4-7.7)  ;  postorbital  constriction,  9.7 
(9-11);  length  of  nasals,  13.4   (12.,S-14.7)  ;  maxillary  tooth  row,  7.7    (7.5-8). 

Remarks. — This  race,  occupying  the  high  plains  at  the  northern 
limit  of  the  range  of  the  species,  is  characterized  mainly  by  being 
smaller  than  the  typical  form.  Specimens  from  Sprague,  Wash., 
are  intermediate  between  Joringl  and  the  typical  race. 

Specimens  examined. — Total  number,  20,  as  follows: 

Washington:  Baird  (Douglas  County),  3;  Cheney,  1;  Coulee  (Grant  County), 
2;  Douglas,  2;  Farmer  (Douglas  County),  2;  Harrington,  1;  Mansfield, 
1;  Moses  Coulee  (Douglas  County),  1;  Sprague,  5;  Waterville,  1;  Wil- 
bur, 1. 


>"Type,  Acad.  Nat.  Sci.  Philadelphia. 
*^  TIniv.  Michigan  Mus.  Zool. 
"  Four  in  Univ.  Michigan  Mus.  Zool. 
"Field  Mus.  Nat.  Hist. 


72  NORTH  AMERICAN  FAUNA  [No.  56 

CITELLUS   BRUNNEUS   Howell 

Idaho  Spotted  Ground  Squiekel 

(Pis.  23,  D;  28,  D) 

Citellus   townsendii  drunneus  Howell,   Biol.    Soc.   Wash.   Proc.   41:   211,   Dec 
18,  1928. 

Type. — Collected  at  New  Meadows,  Adams  County,  Idaho,  July  11, 
1913,  by  L.  E.  Wyman;  female  adult,  skin  and  skull,  no.  201963, 
U.  S.  Natl.  Mus.  (Biological  Survey  collection)   (orig.  no.  178). 

Range. — West  central  Idaho,  in  Washington,  Adams,  and  Valley 
Counties ;  limits  of  range  unknown  (fig.  3) .  Zonal  range:  Transition 
and  Upper  Sonoran. 

External  characters. — Similar  to  C.  washingtoni  wasliingtoni  but 
color  of  upper  parts  more  brownish  (less  grayish)  and  the  dorsal 
spots  smaller;  cinnamon  patch  on  face  darker  and  more  extensive; 
tail  longer  and  darker  (more  blackish)  ;  ears  much  larger,  raised 
conspicuously  above  the  crown.  Compared  with  G.  idahoensis: 
Upper  parts  more  brownish  and  distinctly  spotted;  tail  with  more 
black;  ears  larger. 

Cranial  characters. — Skull  similar  to  that  of  washingtoni  but  aver- 
aging larger  and  relatively  broader,  especially  the  rostrum  and  the 
postorbital  region;  nasals  longer;  last  upper  molar  with  posterior 
Joph  practically  obsolete.  Compared  with  idahoensis:  Skull  averag- 
ing slightly  smaller  but  broader  across  postorbital  region;  nasals 
larger  (both  longer  and  broader) ;  audital  bullae  smaller;  external 
meatus  shorter. 

Color. — Summer  pelage  (July)  :  General  tone  of  upper  parts  smoke 
gray,  more  or  less  heavily  washed  on  the  back  with  pinkish  cinnamon 
or  sayal  brown,  and  moderately  sprinkled  with  small,  quadrangular 
spots  of  grayish  white;  front  of  face  with  a  rather  extensive  patch 
of  sayal  brown ;  eyes  surrounded  with  a  broad  ring  of  creamy  white ; 
sides  of  neck  and  body  faintly  washed  with  pinkish  buff ;  feet  pinkish 
buff ;  thighs  pale  russet ;  tail  above,  dark  sayal  brown  at  base,  shaded 
on  distal  portion  with  fuscous  black  and  all  sprinkled  with  grayish 
Avhite ;  tail  beneath,  cinnamon,  shaded  with  grayish  white  and  fuscous, 
and  edged  with  cinnamon  buff;  under  parts  grayish  white,  shaded 
with  pinkish  buff. 

Measurements. — Average  of  13  adults  from  type  region  (New  Meadows,  Mid- 
vale,  Van  Wyck,  Goodrich,  and  Weiser)  :  Total  length,  232.5  (214-252)  ;  tail 
vertebrae,  56.7  (51-61)  ;  hind  foot,  34.2  (33-37)  ;  ear  from  notch,  10.5  (&-12). 
Skull:  Average  of  5  adult  males  from  Weiser  and  Midvale,  Idaho :  Greatest 
length,  40.1  (38.7^0.8)  ;  zygomatic  breadth,  25.5  (24.9-26.1)  ;  palatilar  length, 
18.6  (18-19)  ;  cranial  breadth,  18.4  (18.1-18.5)  ;  interorbital  breadth,  8.3  (7.5- 
9.2)  ;  postorbital  constriction,  10.9  (10.4-11.6)  ;  length  of  nasals,  14.8  (13.7-16.1)  ; 
maxillary  tooth  row,  8.4  (8.1-8.8).  Average  of  3  adult  females  (including  type)  : 
Greatest  length,  37.3  (36.4-38.2)  ;  palatilar  length,  17.3  (17-18)  ;  zygomatic 
breadth,  23.8  (23.4-24.1)  ;  cranial  breadth,  17.8  (17.2-18.6)  ;  interorbital  breadth, 
7.8  (7.6-8.1)  ;  postorbital  constriction,  10.4  (9.5-11.2)  ;  length  of  nasals,  13.4 
(33.1-13.8)  ;  maxillary  tooth  row,  7.9   (7.5-8.2). 

Remarks. — This  well-marked  species  apparently  has  a  rather  re- 
stricted distribution  in  west-central  Idaho,  where  it  meets  or  slightly 
overlaps  the  range  of  C.  townsendii  mollis  (at  Weiser).  It  is  readily 
distinguished  from  both  idahoensis  and  mollis  by  its  distinct  dorsal 
spotting  and  its  large  ears. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  73 

Originally  described  by  the  writer  as  a  subspecies  of  C.  townsendii 
\_— leashing toni],  it  appears  on  more  detailed  comparison  to  be  a  dis- 
tinct species,  distinguished  from  washingtoni  by  larger  ears,  longer 
and  darker  tail,  smaller  dorsal  spots,  and  by  the  skull  characters 
pointed  out  above. 

Specimens  examined. — Total  number,  14,  as  follows: 

Idaho:  Goodrich   (Adams  County),  1;  Midvale   (Washington  County),  3;  New 
Meadows  (Adams  County),  2;  Van  Wyck  (Valley  County),  2;  Weiser,  6. 

CITELLUS  RICHARDSONn  GROUP 

CITELLUS  RICHARDSONII  (Sabine) 
[Synonymy  under  subspecies] 

SpecifiG  characters. — ^Size  medium  to  large ;  hind  foot  39.5-48  mm ; 
tail  65-100 ;  skull  length  42-48.6.  Dorsal  outline  of  skull  convex,  the 
highest  point  being  between  the  postorbital  processes;  brain  case 
harrow  and  deep,  much  constricted  anteriorly;  postorbital  processes 
long,  slender,  and  decurved;  interorbital  constriction  pronounced; 
zygomata  heavy  and  broad,  widely  expanded  posteriorly,  narrowing 
anteriorly ;  rostrum  moderately  narrow ;  nasals  ending  nearly  on  the 
j)lane  of  the  posterior  ends  of  premaxillae,  or  shorter;  antorbital 
canal  suborbicular ;  upper  tooth  rows  slightly  convergent  poste- 
riorly ;  auditory  bullae  rather  small,  low  and  broad ;  auditory  meatus 
slightly  produced;  upper  incisors  moderately  slender  and  nearly 
straight. 

Coloration  of  upper  parts  drab  or  smoke  gray,  more  or  less  shaded 
with  fuscous  and  dappled  with  cinnamon  buff;  under  parts  pale  buff 
or  cinnamon  buff;  under  side  of  tail  clay  color,  cinnamon  buff,  or 
sayal  brown. 

CITELLUS  RICHARDSONII  RICHARDSONII   (Sabine) 

Richardson's  Gbound  Squirrel 

(Pis.  2;  25,  F;  30,  F) 

Arctomys  richardsonii  Sabine,  Trans.  Linn.  Soc.  London  13 :  589,  1822. 
Arctomys    (Spermophilus)    richardsonii  Richardson,   Fauna   Boreali-Amer.,    p. 

164,  1829. 
Spermophilus  richardsonii  F.  Cuvier,  Sup.  Sl  I'hist.  natur.  Buff  on  1 :  323,  1831. 
[Citellus]  richardsoni  Trouessart,  Cat.  Mamm.,  Sup.,  p.  338,  1904. 

Type  (lectotype).^^ — Collected  at  Carlton  House,  Saskatchewan,  by 
Sir  John  Richardson;  no.  63a,  British  Museum. 

Range. — Plains  of  southern  Alberta,  southern  Saskatchewan,  south- 
western Manitoba,  northern  and  central  Montana,  North  Dakota 
(except  southwestern  part),  and  northeastern  South  Dakota;  north 
to  the  North  Saskatchewan  Eiver;  east  to  the  Red  River  Valley, 
N.  Dak.,  Big  Stone  Lake,  S.  Dak,,  and  the  western  edge  of  Minne- 
sota; south  to  east-central  South  Dakota  (Jerauld  County),  and 
southwestern  Montana  (Gallatin  and  Park  Counties) ;  west  to  the 
foothills  of  the  Rocky  Mountains  in  Alberta  and  Montana  (fig.  4). 
Zonal  range:  Transition. 

External  characters. — Size  large;  hind  foot,  43-47  mm;  tail  about 
one-fourth  the  total  length;  ears  broad  and   low    (2-4  mm  above 


"Selected  by  O.  Thomas  (1927,  p.  545). 


74 


NORTH  AMERICAN  FAUNA 


[No.  56 


crown) ;  coloration  above  nearly  uniform  buffy  or  drab,  with  slight 
"dappling" ;  under  parts  deep  buff  in  summer  pelage. 

Graniaf^  characters. — As  given  under  specific  characters ;  compared 
with*  0.  r.  elegans^  the  skull  is  larger,  with  longer  and  relatively 
narrower  rostrum. 

Color. — Fresh  summer  pelage  (July)  :  General  tone  of  upper  parts 
pinkish  buff  or  cinnamon  buff,  shaded  with  fuscous  (caused  by  ex- 
posure of  the  subterminal  bases  of  the  hairs),  the  posterior  part  of 
back  showing  a  distincthf  "dappled"  effect;  nose  with  a  large  patch 
of  cinnamon;  eye  ring  light  buff;  sides  of  head  and  neck  and  front 
of  fore  le^s  cinnamon  buff  or  clay  color;  sides  of  body  and  under 
parts  pinkish  buff  or  cinnamon  buff ;  hind  feet  pinkish  buff ;  tail  above, 
fuscous  black,  mixed  with  pinkish  buff  and  broadly  edged  with  the 
same;  tail  beneath,  cinnamon  buff  or  clay  color,  edged  with  pinkish 
buff.  In  worn  pelage  much  of  the  buffy  tone  of  the  upper  parts 
is  lacking,  the  general  effect  being  near  smoke  gray. 

Molt. — Apparently  the  molt  may  occur  at  any  time  in  the  spring 
or  summer.     Specimens  taken  in  April  at  Choteau,  Mont.,  are  in  a 

much -worn  pelage 
and  one— a  breeding 
female  —  shows  a 
patch  of  new  hair 
extending  along  the 
middle  of  the  back 
from  the  head  nearly 
to  the  rump.  An- 
other adult  female 
from  Blackfoot, 
Mont.,  June  12,  is  in 
similar  condition  of 
molt.  An  adult  fe- 
male from  Wingard, 
Saskatchewan,  July 
15,  is  much  worn  on 
the  anterior  half  of 
the  body  and  shows 
new  pelage  covering  the  posterior  half  to  the  middle  of  the  back. 

Measurements. — Average  of  16  adults  (7  males,  9  females)  from  type 
locality:  Total  length,  2S5.4  (277-306)  ;  tail  vertebrae,  73.8  (65-83)  ;  hind  foot, 
44.9  (43-47).  Skull:  Average  of  7  adult  males  from  type  locality:  Greatest 
length,  47.7  (47.3^8)  ;  palatilar  length,  23.7  (23-25)  ;  zygomatic  breadth,  31.9 
(30.5-33.5)  ;  cranial  breadth,  20.2  (19.9-20.8)  ;  interorbital  breadth,  9.9  (9.5- 
10.6)  ;  postorbital  constriction,  11.4  (10.8-11.9)  :  length  of  nasals,  17.4  (17-18)  ; 
maxillary  tooth  rovs^,  10.4  (10.2-10.7).  Average  of  8  adult  females  from  type 
locality:  Greatest  length,  46.5  (45.1-48.4);  palatilar  length,  23.1  (22.5-24): 
zygomatic  breadth.  30.4  (29.5-31.2)  ;  cranial  breadth,  19.6  (19-20.9)  ;  interorbital 
breadth,  9.5  (8.8-10)  ;  postorbital  constriction,  11.1  (10.8-11.5)  ;  length  of  nasals, 
16.9  (16-18.1);  maxillary  tooth  row,  10.4  (10-10.9).  Average  of  6  adults  (3 
males,  3  females)  from  Choteau  County,  Mont. :  Greatest  length,  48.1  (46.5- 
49.9)  ;  palatilar  length,  24.4  (23.2-26)  ;  zygomatic  breadth,  32.5  (31.5-33.1)  ; 
cranial  breadth,  20  (19.2-20.8)  ;  interorbital  breadth,  9.8  (8.7-11.7)  ;  postorbital 
constriction,  10.6  (9.8-11.2)  ;  length  of  nasals,  17.8  (17.2-18.7)  ;  maxillary  tooth 
row,  10.5  (10.1-11). 

Weight. — In  spring,  11  to  13  ounces ;  in  fall  16  to  11 V2  ounces  (Bailey,  1926, 
p.  58). 

Remarhs. — Richardson's  ground  squirrel  has  an  extensive  range  in 
the  Great  Plains  region  of  southern  Canada,  Montana,  and  the  Da- 


FiGDKE  4. — Distribution  of  tlie  subspecies  of  Citellus  rich- 
ardsonii:  1,  C  r.  richardsonii ;  2,  C.  r.  elegansj  3,  C.  r. 
nevadensis. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  75 

kotas.  The  species  apparently  has  extended  its  range  southward  in 
South  Dakota  in  recent  years  and  is  now  found  regularly  along  the 
northern  border  of  Jerauld,  Sanborn,  Miner,  and  Lake  Counties,  with 
several  outlying  records  of  occurrence  in  Hanson  County  in  1932. 

It  is  reported  also  to  have  extended  its  range  into  western  Minne- 
sota; Surber  (1932,  p.  58)  states  that  colonies  have  recently  been  es- 
tablished in  Norman  County  and  near  Enok,  Kittson  County;  Louis 
EjQowles  reports  that  these  ground  squirrels  invaded  the  western 
borders  of  the  counties  of  Traverse,  Big  Stone,  and  Lac  qui  Parle  in 
1934. 

In  Gallatin  County,  Mont.,  richardsonii  grades  into  the  smaller  and 
darker  race,  elegans^  which  occupies  most  of  the  southwestern  corner 
of  the  State. 

Specimens  examined. — Total  number,  349,  as  follows : 

Alberta:  Calgary,  8;"  Red  Deer,  7. 

Manitoba:  Brandon  (IS  miles  east) ,  1 ;"  Carberry,  56 ;  Petrel  (Norfolk  District) ,  1. 

Montana:  Blackfoot  (Glacier  County),  11;  Blackfoot  Agency  (Glacier  County), 
6;  Big  Belt  Mountains  (Meagher  County,  south  of  Fort  Logan),  3;  Big 
Timber  Creek,  Crazy  Mountains  ( Sweetgrass  County ) ,  4 ;  Birch  Creek 
(Teton  County),  4;  Bozeman,  10;  Bruno  (Meagher  County),  3;'^  Buffalo 
(Fergus  County),  1;  Chief  Mountain  (Glacier  County),  1;  Choteau,  11; 
Dry  Creek  (Gallatin  County),  2;  East  Gallatin  River,  4;  Flat  Willow  Creek, 
3.24  Yovt  Ellis  (near  Bozeman),  1;  Frenchmans  River  (at  international 
boundary),  4;  Glasgow,  5;  Great  Falls,  1;  Grafton  (Judith  Basin  County), 
1;  Johnson  Lake  (Roosevelt  County),  2;  Lewistown,  3;  Livingston,  5; 
Manhattan  (Gallatin  County),  2;  Martinsdale  (10  miles  east,  Wheatland 
County),  2;  Milk  River  (at  mouth,  at  49°,  and  at  Two  Forks),  5;  Moccasin 
Mountains  (Fergus  County),  3;  Philbrook  (Judith  Basin  County),  1;  Ring- 
ling  (10  miles  south,  Meagher  County),  3;'^  Roy  (Fergus  County),  1;  St. 
Mary,  Glacier  National  Park,  11;=^  Sedan  (Gallatin  County),  2;'^  Shelby 
Junction,  5;  Summit  (near  Ringling,  Meagher  County),  1;  Sun  River  Cross- 
ing (Cascade  County),  1;  Teton  (Choteau  County),  1;  Three  Buttes  (on 
International  boundary,  Hill  County),  15;  Toston  (Broadwater  County), 
1;-^  Townsend  (Broadwater  County),  3;"  Tyler  (Fergus  County),  1;  Ubet 
(Wheatland  County),  5;  West  Gallatin  River  (Lower  Basin),  1;  West 
Gallatin  and  Spanish  Canyons  (Gallatin  County),  3.^ 

North  Dakota:  Ashley,  1;  Bismarck,  11;  Bottineau,  8;  Bowdon,  2;"  Buford 
(Williams  County),  6;  Crosby,  1;  Devils  Lake,  15;  Drayton,  6;  Ellendale, 
1 ;  Grafton,  G ;  Hankinson,  1 ;  Kenmare,  1 ;  LaMoure,  6 ;  Larimore,  2 ;  Lisbon, 
1;  Lostwood  (Mountrail  County),  1;  Pembina,  2;  Rush  Lake  (Cavalier 
County),  2;  St.  John  (Rolette  County),  2;  Starkweather  (Ramsey  County), 
1;  Stump  Lake  (Nelson  County),  1 ;""  Towner,  1;  Turtle  Creek  (near  Wash- 
burn), 1;  Turtle  Mountains,  2;  Washburn,  4. 

Saskatchewan :  Carleton,  5 ;  Indian  Head,  3 ;  Livelong,  1 ;  *"  Moosejaw,  3 ;  Win- 
gard,  20. 

South  Dakota :  Aberdeen,  2 ;  Frederick,  4 ;  Wahvorth  County.  1. 


22  Five  in  collection  of  C.  B.  Garrvtt. 

23  Kansas  Univ.  Mus. 

2<  Montana  Slate  College. 
25  Univ.  Michigan  Mus.  Zool. 
2«  William  T.  Shaw  coll. 
27  Carnegie  Mus. 


76  NORTH  AMERICAN  FAUNA  [No.  56 

CITELLUS    RICHARDSONII    ELEGANS    (Kennicott) 

Wyoming  Ground  Squireel 

(Pis.  25,  E;  30,  E) 

Spermophilus  elegans  Kennicott,  Acad.  Nat.  Sci.  Phila.  Proc.  .186.3:  158. 
ISpermophilus  ricliardsoni]   var.   elegans  Allen,  Boston   Soc.   Nat.  Hist.   Proc. 

16:  292,  1874. 
ISpermophilus  richardsoni]  var.  townsendi  Allen,  Monog.  North  Amer.  Rodentia, 

p.  850,  859,  1877  (part). 
[Citellus]  elegans  Trouessart,  Cat.  Mamm.,  Sup.,  p.  339,  1904. 

Cotypes. — Collected  at  Fort  Bridger,  Wyo.,  April  and  May  1858, 
by  C.  Drexler;  female,  skin  and  fragments  of  skull,  no.  |||^  ;  male, 
skin  and  part  of  skull  inside,  no.  3480;  skin  no.  5955 ;  skin  (in  alcohol) 
and  skull,  no.  ffff ;  alcoholics,  nos.  5951,  5952,  5953,  5954;  also,  a  few 
other  fragments  in  U.  S.  Natl.  Mus.  (Lyon  and  Osgood,  1909,  p.  165). 

Range. — Southwestern  Montana,  southeastern  Idaho,  southern 
Wyoming,  and  northwestern  Colorado;  north  to  Madison  and 
Beaverhead  Counties,  Mont.,  and  northwestern  Converse  County, 
Wyo.;  east  to  extreme  southeastern  Wyoming;  south  to  Leadville, 
Colo.;  west  to  Custer  County  (Big  Lost  River  Valley),  Idaho  (fig. 
4) .    Zonal  range :  Mainly  Transition. 

External  characters. — Similar  to  C.  r.  richardsonii  but  smaller, 
with  shorter  hind  feet;  coloration  of  upper  parts  in  summer  less 
buffy  (more  grayish  or  brownish) ;  under  parts  and  sides  of  head 
and  shoulders  paler  in  summer  pelage;  tail  usually  darker  and  more 
blackish  beneath,  but  with  paler  edgings. 

Cranial  characters. — Skull  similar  to  that  of  richardsonii  but 
smaller;  rostrum  shorter  and  relatively  broader;  nasals  shorter. 

Color. — General  tone  of  upper  parts  light  drab,  more  or  less 
flecked  with  light  pinkish  buff,  some  specimens  showing  a  decided 
pinkish  or  brownish  tone  on  the  middle  of  the  back,  the  head  and 
shoulders  frequently  more  or  less  washed  with  smoke  gray;  nose 
cinnamon  buff,  clay  color,  or  pinkish  cinnamon;  eye  ring  white  or 
buffy  white ;  feet  pinkish  buff  or  ivory  yellow ;  tail  above,  similar  on 
basal  portion  to  the  back,  the  terminal  half  broadly  bordered  with 
fuscous  black  and  edged  with  pale  buff ;  tail  beneath,  cinnamon  buff 
or  pale  cinnamon,  bordered  on  terminal  portion  with  fuscous  black ; 
lower  sides  and  under  parts  cartridge  buff. 

Measurements. — Average  of  10  adults  from  Fort  Bridger  and  New  Fork  of 
Green  River,  Wyo.:  Total  length,  262.3  (253-272)  ;  tail  vertebrae,  72.9  (66-78)  ; 
hind  foot,  40.7  (39.5-43).  Skull:  Average  of  12  adults  (9  males,  12  females) 
from  vicinity  of  type  locality  (Fort  Bridger,  Evanston.  Cumberland,  Lone 
Tree)  :  Greatest  length,  43.1  (42^4.8)  ;  palatilar  length,  20.9  (20-22.2)  ;  zvgo- 
matic  breadth,  28.8  (27.5-30)  ;  cranial  breadth,  19.7  (18.7-20.5)  ;  interorbital 
breadth,  9.3  (8.5-10)  ;  postorbital  constriction,  11.3  (10.5-11.7)  ;  length  of  nasals, 
15.3  (14.7-16.1);  maxillary  tooth  row,  9.4  (9-9.7). 

Remarks. — The  Wyoming  ground  squirrel  was  originally  de- 
scribed by  Kennicott  as  a  distinct  species.  Allen  (18YT,  p.  850),  cor- 
rectly associated  it  with  C.  richardso^iii  as  a  variety,  but  misapplied 
Bachman's  name  townsendii  to  it.  It  continued  to  be  known  by  that 
name  until  1891,  when  Merriam  revived  Kennicott's  name  for  it  and 
suggested  that  it  might  prove  to  be  a  subspecies  of  richardsonii.  The 
material  now  available  shows  this  to  be  the  case,  intergradation  be- 
tween the  two  forms  occurring  in  Gallatin  County,  Mont.  Speci- 
mens of  elegans  in  winter  pelage  are  scarcely  distinguishable  from 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  77 

comparable  specimens  of  C .  r.  ridiardsonii^  except  by  their  smaller 
size,  but  in  summer  pelage  elegans  is  decidedly  grayer  and  less  buffy. 
Specimens  examined. — Total  number,  229,  as  follows : 

Colorado:  Canadian  Creek  (North  Park),  3;  Coulter  (Grand  County),  6;  Elk- 
horn  (Larimer  County,  near  Log  Cabin),  2;  Estes  Park,  1;^  Fairplay,  2; 
Fish  Creek  (Routt  County),  2;  Fort  Collins  (Buckhorn  Ranger  Station), 
6;  Garo  (Park  County),  1;  Leadville  (10  miles  south),  2;^  Mount  Whitely 
(Grand  County),  1;  Rabbit  Ear  Mountains  (Jackson  County),  1;  Sopris 
National  Forest  (west  of  Thomasville),  1;  Steamboat  Springs  (15  miles 
west),  3;  Wolcott  (Eagle  County),  1.=° 

Idaho:  Birch  Creek  (Clark  County),  5;  Dickey  (Custer  County),  10;  Forney, 
1:  Henry  Lake,  1;  Lemhi  Mountains  (west  of  Junction),  1;  Montview,  1; 
Patterson  (Bingham  County),  3;  Pleasant  Valley  (Clark  County),  1. 

Montana:  Alder,  1;  Big  Hole  Bench  (west  of  Wisdom,  Beaverhead  County),  1; 
Dillon,  14  ;  ^  Ennis  Lake,  2  ;  Harrison,  3  ;  Lakeview,  2  ;  Lower  Bedrock  Lake 
(Beaverhead  County),  1;'*  Pony  (Madison  County),  1;  Red  Bluff  (Madi- 
son County),  1;  Virginia  City,  5;  Wisdom  (9  miles  north,  Beaverhead 
County),  3." 

Wyoming:  Altvan  (Laramie  County),  1;  Bear  Creek  (Albany  County,  near 
Eagle  Peak),  1;  Big  Piney  (Sublette  County),  1;  Big  Sandy  (Sublette 
County),  2;  Bitter  Creek,  5;'^  Bridger  Pass  (Sweetwater  County),  7; 
Bridger  Peak,  Sierra  Madre  Mountains,  1 ;  Cheyenne,  8 ;  Cokeville,  6 ;  Cum- 
berland, 9;  Evanston,  4:  Fort  Bridger  (Uinta  County),  18;  Fort  Russell 
(Laramie  County),  6;  Fort  Saunders  (=Laramie),  1;  Fort  Steele  (Carbon 
(IJounty),  2;  Fossil  (Lincoln  County),  8;  Green  River  (City),  3;  Green  River 
(at  mouth  of  New  Fork),  5 ;  Islay  (Laramie  County),  2 ;  Kemmerer,  1 ;  Kin- 
ney Ranch  (Bitter  Creek.  Sweetwater  County),  3;  Laramie,  1;  Laramie 
River,  1 ;  Laramie  Mountains,  3 ;  Little  Medicine  Bow  River  (Carbon 
County),  1;  Little  Piney  Creek  (Sublette  County),  1;  Lonetree  (Uinta 
County),  9;  Medicine  Bow  ^Mountains,  2;  Mountainview  (Uinta  County), 
2;  New  Fork,  Green  River  (Lander  Road),  4;  Opal  (Lincoln  County),  1; 
Pinedale,  2;  Poison  Spider  Creek  (Natrona  County),  1;  Pole  Mountain  (15 
miles  southeast  of  Laramie),  2;  Rawlins,  2;  Riverside  (Carbon  County), 
1;  Sage  (Lincoln  County),  4;  South  Pass  City  (Fremont  County),  1;  Supe- 
rior, 4;  Woods  P.  O.   (Medicine  Bow  Mountains,  Albany  County),  4. 

CITELLUS  RICHARD  SONII  NEVADENSIS  Howell 

Ne:\-ada  Ground  Squirrel 

Citellus  elegans  nevadensis  Howell,  Biol.  Soc.  Wash.  Proc.  41:  211,  Dec.  18,  1928. 

Type. — Collected  at  Paradise,  Plumboldt  County,  Nev.,  March  3, 
1908,  by  Stanley  E.  Piper;  female  adult,  skin  and  skull;  no.  156788, 
U.  S.  Natl.  Mus.  (Biological  Survey  collection)    (orig.  no.  112). 

Range. — Northern  Nevada,  extreme  southeastern  Oregon,  and  ex- 
treme southwestern  Idaho;  from  Paradise  Valley,  east  to  Metropolis 
and  south  to  Kuby  Valley,  Nev.  (fig.  4).  Zonal  range:  Upper 
Sonoran  and  Transition. 

External  characters. — Similar  to  C.  r.  elegans  but  larger,  with 
longer  tail  and  hind  feet;  upper  parts  averaging  more  grayish  (less 
brownish),  especially  on  head  and  shoulders;  under  parts  darker 
buff.  Compared  with  G.  heldingi  oregonus:  Size  larger;  upper  parts 
paler  and  more  buffy  (less  reddish)  ;  under  parts  more  buffy;  tail 
paler  and  less  reddish  beneath. 

Cranial  characters. — Skull  similar  to  that  of  elegans  but  averaging 
decidedly  larger;  postorbital  constriction  averaging  less.    Compared 


28  Univ.  of  Michigan  Mus.  Zool. 

™  State  Hist.  Soc.  of  Colorado  (Denver). 

*>  Eight  in  Kansas  Univ.  Mus.  Nat.  Hist. 

»i  Montana  State  College. 

aa  Field  Mus.  Nat.  Hist. 


78  NORTH  AMERICAN  FAUNA  tNo.  56 

with  G.  r.  richardsonii :  Skull  averaging  slightly  larger,  with  broader 
rostrum,  nasals,  and  audital  bullae ;  tooth  row  shorter. 

Color. —  (Type,  March  3) :  Patch  on  front  of  face  mikado  brown 
(varying  in  other  specimens  to  wood  brown  or  pinkish  cinnamon) ; 
head  and  shoulders  smoke  gray,  shaded  with  fuscous ;  eye  ring  broad, 
buffy  white ;  back  smoke  gray  shaded  with  cinnamon  buff,  the  median 
area  darkened  with  fuscous;  feet  pinkish  buff;  tail  above,  mixed 
fuscous  and  pinkish  buff,  edged  with  pale  buff;  tail  beneath,  sayal 
brown,  tipped  with  fuscous;  lower  sides  and  under  parts  cinnamon 
buff,  shading  to  pale  buff  on  chin  and  throat. 

Measurements. — Type  (?  ad.,  from  dry  skin)  :  Total  length,  337;  tail  verte- 
brae, 100;  hind  foot,  47.  Average  of  9  adults  from  Ruby  Valley,  Skelton,  and 
McDermitt,  Nev. :  Total  length,  291.1  (270-307)  ;  tail  vertebrae,  88.1  (7&-100)  ; 
hind  foot,  46.1  (42--48).  BUull:  Average  of  6  adults  (3  males,  3  females)  from 
Paradise,  Metropolis,  and  McDermitt,  Nev. :  Greatest  length,  47  (44.7-48.6)  ; 
palatilar  length,  23  (22-24)  ;  zygomatic  breadth,  31.3  (29.9-32.4)  ;  cranial 
breadth,  20.9  (19.6-21.7)  ;  interorbital  breadth,  10  (9.2-11.6)  ;  postorbital  con- 
striction, 10.6  (9.7-11.5)  ;  length  of  nasals,  17.7  (17-18.6)  ;  maxillary  tooth  row, 
9.6  (9.3-10.3). 

Remarks. — The  Nevada  ground  squirrel  is  fully  as  large  as  typical 
richardsonii  but  is  grayer  and  less  buffy  and  the  tail  is  darker  and 
more  tawny  beneath.  It  undoubtedly  intergrades  with  elegans,  but 
its  range  as  at  present  known  appears  to  be  isolated  from  the  range 
of  that  race.  It  overlaps  the  range  of  oregonus.,  occurring  often  in 
the  same  localities,  but  the  two  are  quite  distinct. 

Specimens  examined. — Total  number,  33,  as  follows : 

Idaho:  Riddle  (Owyhee  County),  l.** 

Nevada:  Elko,  9;  Metropolis,  5;  Mountain  City   (Elko  County),  2;  Paradise 

(Humboldt  County) ,  2  ;  Ruby  Valley,  5  ;  Skelton  (30  miles  south  of  Elko) ,  2. 
Oregon:  Malheur  County    (near  McDermitt,  Nev.),  4;  Rattlesnake  Creek   (at 

head,  Malheur  County),  3. 

CITELLUS  ARMATUS    (Kennicott) 

Uinta  Gkound  Squirrel 

(Pis.  23,  F;  28,  F) 

Spermophiliis  armatus  Kennicott,  Acad.  Nat.  Sci.  Phila.  Proc.  1863:  158. 
[Cifellus]    armatus   Trouessart,   Cat.   Mamm.,    Sup.,   p.   339,   1904. 

Cotypes. — Collected  in  the  foothills  of  the  Uinta  Mountains,  near 
Fort  Bridger,  Wyo.,  April  to  June  1858,  by  C.  Drexler;  nos.  3464 
and  3476,  skins  [fragmentary]  with  skulls  inside;  nos.  4794,  4808, 
4809,  fragmentary  skulls ;  nos.  5958,  5959,  5960,  alcoholics  (Lyon  and 
Osgood,  1909,  p.  163). 

Range. — Mountains  and  foothills  of  western  Wyoming,  extreme 
southwestern  Montana,  southeastern  Idaho,  and  northern  and  central 
Utah;  north  to  Beaverhead,  Madison,  Gallatin,  and  Park  Counties, 
Mont. ;  east  to  the  eastern  foothills  of  the  Shoshone  and  Wind  River 
Mountains,  Wyo. ;  south  to  Fish  Lake  Plateau,  Utah ;  west  to  Dono- 
van, Mont.,  Mount  Harrison,  Cassia  County,  Idaho,  and  the  Raft 
River  Mountains,  Utah  (fig.  5).  Zonal  range:  Canadian  and  Transi- 
tion. 

Ea;ternal  characters. — Similar  to  G.  richardsonii  elegans^  but 
slightly  larger,  with  longer  hind  feet,  tail  of  nearly  the  same  length ; 
ears  larger;  upper  parts  decidedly  darker;  tail  more  grayish  (less 

«Mus.  Vert.  Zool. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


79 


buffy)  beneath.  Compared  with  C.  teldingi  oregonus:  Closely  sim- 
ilar in  size  and  coloration,  but  dorsal  region  slightly  darker,  the 
rmnp  and  thighs  more  tawny  (less  grayish) ;  tail  grayish  rather  than 
reddish  beneath,  the  bordering  hairs  more  buffy  (less  grayish). 

Cranial  characters. — Skull  similar  to  that  of  G.  r.  richardsonU  but 
averaging  slightly  longer,  and  narrower  across  zygomata;  cranium, 
interorbital  region,  and  rostrum  broader,  but  postorbital  constriction 
less ;  audital  bullae 
broader,  with  longer 
meatus;  nasals 
slightly  longer ;  max- 
illary tooth  row 
shorter.  Compared 
with  elegans:  Decid- 
edly larger,  with 
broader  rostrum  and 
interorbital  region, 
and  longer  and 
broader  nasals.  Com- 
pared with  C.  r.  ne- 
vadensis:  Similar  in 
size,  but  averaging 
broader  across  zygo- 
mata; brain  case 
and  audital  bullae 
broader.  Compared 
with  C.  h.  oregonus: 
Skull  slightly  larger ; 
nasals  averaging 
broader  at  posterior 
end. 

Color. —  ( Fresh 
pelage,  June  12)  : 
Head,  front  of  face, 
and  ears  cinnamon, 
sprinkled  on  crown 
with  gray;  sides  of 
face  and  neck  pale 
smoke  gray;  eye  ring  cartridge  buff;  front  legs  cinnamon  buff,  shad- 
ing to  pinkish  buff  on  feet ;  general  tone  of  dorsal  area  sayal  brown 
or  cinnamon  buff,  the  hairs  tipped  with  pinkish  buff,  bases  of  the 
hairs  fuscous;  sides  paler  than  back,  mixed  cartridge  buff  and  fus- 
cous; thighs  cinnamon;  hind  feet  pinkish  buff;  tail,  above  and  below, 
fuscous  black,  mixed  with  pale  buff  or  buffy  white,  and  edged  with 
pinkish  buff;  under  parts  pinkish  buff,  shaded  with  buff'y  white. 

Variation. — The  intensity  of  the  brownish  color  on  the  back  varies 
considerably  in  different  individuals;  certain  specimens,  taken  botli 
in  midsummer  and  early  spring,  have  the  brownish  tone  much 
reduced,  the  hairs  on  the  median  dorsal  area  being  pinkisli  buff  and 
the  wliole  back  and  sides  washed  with  grayish  white.  Two  specimens 
from  Mountainview,  Wyo.,  are  uniform  blackish  brown  all  over. 

Molt. — The  molting  period  is  not  clearly  shown  in  the  specimens 
examined,  but  probably  in  most  individuals  the  molt  occurs  in  June, 
or  sometimes  in  May.    A  male  from  Hamsfork,  Wyo.,  taken  May 


Fiauui:  3. — Distribution  of  Citcllus  annatus. 


go  NORTH  AMERICAN  FAUNA  [No.  56 

17,  is  in  badly  worn  pelage,  and  shows  a  few  small  patches  of  new 
hair  on  the  back.  A  nursing  female  from  Spring  Valley,  Wyo., 
June  9,  is  likewise  in  a  much  worn  pelage,  with  new  hair  covering 
the  head  and  fore  back.  An  adult  male  from  Cooke,  Mont.,  August 
11,  shows  worn  hair  on  the  anterior  half  of  the  body  and  a  fuller, 
unworn  pelage  on  the  posterior  half. 

Measurements. — ^Average  of  12  adults  from  vicinity  of  tyue  locality :  Total 
length,  294  (280-303)  ;  tail  vertebrae,  72.6  (63-81)  ;  Mnd  foot,  43.9  (42^5.5)  ; 
ear  from  notch,  11.2  (10-12).  Skull:  Average  of  7  adult  males  from  south- 
western Wyoming  and  Barclay,  Utah:  Greatest  length,  47.8  (46.3-48.5)  ;  palat- 
ilar  length,  23.2  (22.5-24)  ;  zygomatic  breadth,  31  (30-31.8)  ;  cranial  breadth, 
20.7  (19.2-21.5)  ;  interorbital  breadth,  11  (10-11.3)  ;  postorbital  constriction, 
10.9  (10.4-11.5)  ;  length  of  nasals,  17.8  (16.4-18.4)  ;  maxillary  tooth  row,  9.7 
(9.3-10).  Average  of  6  adult  females  from  Fort  Bridger  and  Spring  Valley, 
Wyo.:  Greatest  length,  46.5  (45.6-48)  ;  palatilar  length,  22.2  (22-23)  ;  zygomatic 
breadth,  30.2  (29.6-30.8)  ;  cranial  breadth,  20.1  (19.8-20.4)  ;  interorbital  breadth, 
10.2  (9.4-11.3)  ;  postorbital  constriction,  11.3  (10-12.3)  ;  length  of  nasals,  17.2 
(16.&-17.9)  ;  maxillary  tooth  row,  9.8  (9.4-10.2). 

Remarks. — The  Uinta  ground  squirrel  is  a  distinct  species,  occupy- 
ing a  rather  limited  area  in  the  mountains  from  southern  Montana 
south  to  Utah.  It  most  nearly  resembles  oregonus,  but  the  two  are 
quite  distinct  and  so  far  as  known  their  ranges  do  not  meet.  The 
range  of  armatus  meets  and  slightly  overlaps  that  of  elegans  in  parts 
of  Montana  and  Wyoming,  but  in  general  this  species  occurs  at  higher 
altitudes  and  in  more  heavily  wooded  areas  than  does  elegans.  In 
some  localities,  however,  as  at  Pinedale  and  Cokeville,  Wyo.,  the  two 
species  occupy  the  same  ground. 

Specimens  examined. — Total  number,  263,  as  follows: 

Idaho:  American  Falls,  1;  ^  Arco  (Butte  County),  4;  '^  Big  Hole  Mountains,  1; 
Blackfoot,  4;  Blackfoot  Mountains,  1;  Clifton  (Franklin  County),  1;  Elba 
(Cassia  County),  1;^°  Irwin  (10  miles  southeast,  Bonneville  County),  5; 
Malta  (Cassia  County),  1;^°  Montpelier,  7;  Mount  Hai-rison  (Cassia 
County),  1;^°  Pahsimeroi  River  (head,  Custer  County),  1;^  Pocatello,  6; 
Shelley,  1;  Swan  Lake  (Bannock  Courity),  6;  Teton  Canyon,  1;  Warm 
River  (Fremont  County),  1.^* 

Montana:  Cooke  (Park  County),  11;  Donovan  (Beaverhead  County),  1;  Ennis 
Lake  (Madison  County),  2;  Lakeview  (Beaverhead  County),  13;  Spanish 
Creek  (Gallatin  County),  3;  Virginia  City  (Eight-mile  Spring),  4;  Vir- 
ginia City  (20  miles  south),  3 ;  Ward  Peak  (Tobacco  Root  Mountains,  Mad- 
ison County),  6;  West  Boulder  Creek  (18  miles  southeast  of  Livingston), 
3;  West  Gallatin  River  (West  Fork,  Gallatin  County),  4;  West  Gallatin  and 
Spanish  Canyons  (Gallatin  County),  9.'" 

Utah:  Barclay  (Salt  Lake  County),  8;  Blacksmiths  Fork  (Cache  County),  1; 
Big  Cottonwood  Canyon  (Salt  Lake  County),  1;"  Bountiful,  1;  Currant 
Creek  (Wasatch  County),  2;  Fairview  (Mammoth  Ranger  Station),  2; 
Farmington,  2;  Fish  Lake  (Sevier  County),  1;  Fruitland,  3;*^  Hyde  Park 
(Cache  County),  1;  Laketown  (Rich  County),  2:  Lakota,  Bear  Lake,  1  ;^' 
Logan  Canyon  (Cache  County),  1;'^  Mantua  (Box  Elder  County),  1;^  Mount 
Pleasant,  1;  Mount  Timpanogas  (Utah  County),  2;^  Ogden"(Ogden  Can- 
yon), 1;  Park  City,  17;  Raft  River  Mountains,  1;''  Salt  Lake  City  (Fort 
Douglas),  3;  Sardine  Canyon  (Cache  County),  2;'*  Strawberry  Valley  (Du- 
chesne County),  9;  Wellsville,  4. 

Wyoming:  Afton  (Lincoln  County),  11;  Border  (Lincoln  County),  5;  Clarks 
Fork  (opposite  Crandall  Creek,  Park  County),  1 ;  Cokeville,  6;  Daniel  (Sub- 
lette County),  13;  Evauston,  4;   Fort  Bridger,  S;   Gros  Ventre  Mountains 

**  Donald  R.  Dickey  collection. 

s^Mus.  Vert.  Zool. 

88  Montana  State  College,  Bozeman. 

^  Acad.  Nat.  Sci.  Philadelphia. 

^  Brigham  Young  Univ. 

s9  Utah  State  Agr.  College. 

*i  Carnegie  Mus. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


81 


(Waterdog  Lake),  S;^  Hamsfork  (Lincoln  County),  2;  Jackson,  5;  Jakeys 
Creek  (Fremont  County),  1;  Kemmerer,  7;  Kendall  (12  miles  north,  Sub- 
lette County),  2;  Little  Piney  Creek  (8,000  feet  altitude,  Sublette  County), 
1;  Merna  (Sublette  County),  1;  Mountainview  (Uinta  County),  7;  Opal 
(Lincoln  County),  2;  Pahaska  (mouth  of  Grinnell  Creek,  Park  County),  1; 
Spring  Valley  (Uinta  County),  2;  Stanley  (8,000  feet  altitude,  Sublette 
County),  1;  Valley  (Park  County),  5;  Wind  River  Mountains  (Upper  Gros 
Ventre  River,  North  Fork),  1;  Wyoming  Peak  (10,900  feet  altitude,  Lincoln 
County),  1;  Yellowstone  National  Park,  4. 

CITELLUS  BELDINGI 

(Mereiam) 

[Synonymy  under  sub- 
species] 

Specific  charac- 
ters.— Slightly  small- 
er than  G.  r.  richard- 
sonii;  hind  foot,  41- 
47  mm;  tail,  55-76; 
skull  length,  41.3- 
46.3.  Skull  similar 
to  that  of  O.  r.  ele- 
gans  but  relatively 
longer,  and  narrower 
across  zygomata,  but 
broader  interorbit- 
ally;  zygomata  slen- 
derer ;  audital  bullae 
smaller.  Coloration 
of  upper  parts  smoke 
gray,  mixed  with 
pinkish  buff,  the  me- 
dian dorsal  area 
more  or  less  dark- 
ened ;with  sayal 
brown  or  kaiser 
brown ;  under  side  of 
tail  hazel,  upper  side 
mixed  with  fuscous. 


Figure  6. — Distribution  of  the  subspecies  of  Citellus   bel- 
dingl:   1,    C.   6.   oregonus;   2,    C.    6.    beldingi. 


CITELLUS  BELDINGI   BELDINGI    (Merriam) 

Bei.ding's  Ground  Squirrel 

(Pis.  3;  23,  E;  28,  E) 

Spermophilus  heldingl  Merriam,  Ann.  N.  Y.  Acad.  Sci.  4 :  317,  Dec.  28,  1888. 
[Citellus]  beldingi  Trouessart,  Cat.  Mamm.,  Sup.,  p.  339,  1904. 


Type.— Collected  at  Donner,  Placer  County,  Calif.,  June  22,  1886, 
by  Cliarles  A.  Allen;  female  adult,  skin  and  skull,  no.  186467,  U.  S. 
Natl.  Mus.  (formerly  no.  -VgVrj  Merriam  collection)  (orig.  no.  103). 

Range. — High  mountain  meadows  in  the  central  Sierra  Nevada, 
from  Nevada  County  (Independence  Lake)  south  to  the  headwaters 
of  Kings  River,  Fresno  County,  Calif,  (fig.  6).  Zonal  range:  Hud- 
sonian  and  Canadian,  6,500-11,800  feet  altitude  {jide  Grinnell). 

External  characters.— '^'wmX^x  to  G.  arrnaius^  but  upper  parts 
darker  and  more  reddish,  the  reddish  color  on  the  back  usually  in  a 
well  defined  band;  tail  reddish  instead  of  grayish  beneath. 


*"  Cleveland  Mus.  Nat.  Hist. 
154070—38 6 


g2  NORTH  AMERICAN  FAUNA  [No.  56 

Cranial  characters. — Skull  similar  to  that  of  G.  richardsonii  ele- 
gans  (as  defined  under  specific  characters) ;  smaller  than  that  of 
armatus,  with  relatively  broader  interorbital  region  and  less  widely 
expanded  zygomata. 

Color. — Front  of  face  sayal  brown,  shading  to  hazel  on  top  of  head ; 
sides  of  face  and  head  mixed  fuscous  and  pinkish  buflf ;  eye  rmg 
buffy  white;  nape  mixed  light  buff  and  hazel;  dorsal  band  (from 
nape  to  rump)  hazel  or  kaiser  brown  (rarely  sayal  brown) ;  sides  of 
body  mixed  smoke  gray  and  pinkish  buff;  feet  pinkish  buff;  thighs 
cinnamon  or  sayal  brown ;  tail  above  mixed  hazel  and  fuscous  black ; 
tail  beneath,  hazel,  bordered  with  tilleul  buff  and  tipped  with  fus- 
cous black ;  under  parts  dull  whitish,  more  or  less  washed  with  pink- 
ish buff. 

Molt. — In  the  series  examined  there  are  no  specimens  that  show 
clearly  when  these  ground  squirrels  change  their  pelage.  Grinnell 
and  Dixon  (1918,  p.  659)  consider  that  the  species  has  but  one  molt 
annually,  during  July. 

Measurements. — Average  of  12  adults  (8  males,  4  females)  from  type  local- 
ity: Total  length,  279.6  (268-296)  ;  tail  vertebrae,  68  (60-75)  ;  hind  foot,  44.3 
(42— i7).  Skull:  Average  of  10  adult  males  from  type  locality:  Greatest  length, 
45.2  (44-46.3)  ;  palatilar  length,  21.8  (21-22.7)  ;  zygomatic  breadth,  28.8  (27.8- 
29.8)  ;  cranial  breadth,  19.5  (18.7-20.2)  ;  interorbital  breadth,  11.2  (10.5-11.9)  ; 
postorbital  constriction,  11.7  (10.9-12.7)  ;  length  of  nasals,  16.9  (16.1-17.5)  ; 
maxillary  tooth  row,  9.2  (9-9.4).  Average  of  10  adult  females  from  tyiae 
locality:  Greatest  length,  44.7  (43.2-45.7);  palatilar  length,  21.8  (21-22.8); 
zygomatic  breadth,  28.9  (28.2-29.6)  ;  cranial  breadth,  19.5  (19.1-19.8)  ;  inter- 
orbital breadth,  11.1  (10.7-11.8)  ;  postorbital  constriction,  11.7  (11.1-12.5)  ; 
length  of  nasals,  16.1   (15.2-17.1)  ;  maxillary  tooth  row,  9.5   (9.2-10). 

Wei£^7il— Average  of  10  adult  males,  222  g  (125.5-285)  ;  of  10  adult  females, 
240  (172-^05)    (Grinnell  and  Dixon,  1918,  p.  660). 

Remarks. — Belding's  ground  squirrel,  usually  considered  to  be 
a  distinct  species,  proves  on  examination  of  abundant  material  to  be 
subspecifically  related  to  C.  ieldingi  oregonus.  It  is  rather  strictly 
confined  to  the  alpine  meadows  in  the  Sierra  Nevada  of  California, 
and  there  appears  to  be  a  gap  of  about  25  miles  between  its  range 
and  that  of  oregonus.  Notwithstanding  this  apparent  hiatus  be- 
tween their  ranges,  there  is  complete  intergradation  in  characters 
between  the  two  forms. 

Specimens  examined. — Total  number,  236,  as  follows: 

California:  Alpine  City,  Bear  Valley  (Mariposa  County),  1;  American  River 
(head  of  South  Fork,  near  Silver  Lake),  2;  Bishop  Creek  (Inyo  County), 
2;  Donner  (Placer  County,  including  "Summit"),  97;  Diamond  Valley 
(Alpine  County),  1;^^  Fredericksburg  (Alpine  County),  1;*^  Hope  Valley 
(Alpine  County),  4 ;  *V Independence  Lake  (Nevada  County),  13;  Johnson 
Pass  (8  miles  south  of  Lake  Tahoe),  1:  Kaiser  Pass  (Fresno  County),  1;  *^ 
Little  Pete  Meadow  (near  head  of  Middle  Fork  of  Kings  River,  Fresno 
County)  1;**  Long  Valley  (Mono  County),  2;*^  Mammoth  (Mono  County), 
3 ;  McKinneys,  Lake  Tahoe,  7 ;  Mono  Lake,  4 ;  *^  Mono  Pass,  3 ;  Mount 
Dana  (Mono  County),  3;  Mount  Conness  (Tuolumne  County),  1;  Mount 
Tallac  (Eldorado  County),  2;  Owens  River  (at  head),  12;  Pine  City  (Mono 
County,  near  Mammoth  Pass),  1;  Post  Corral  Meadows  (Fresno  County), 
2;**  Sand  Meadow  (Fresno  County),  1;**  San  Joaquin  River  (near  Mam- 
moth Pass),  2;  Sonora  Pass  (Alpine  County),  2;  Tahoe  (Placer  County), 
3;  Terrace  Meadow  (Inyo  County),  1;**  Tioga  Pass  (Mono  County),  1 ;  *" 
Walker  Lake  (Mono  County),  1 ;  *^  Woodf ords  (Alpine  Coimty),  5;"^  Yosem- 
ite  National  Park,  52   (including  Lake  Tenaya,  7;  head  of  Lyell  Canyon, 


■^Mus.  Vert.  Zool. 

«Wm.  T.  Shaw  Collection. 

"  Cleveland  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  83 

6 ;  ^  Merced  Lake,  1 ; ''  Mount  Hoffman,  4 ;  ^  Mt.  Lyell,  1 ;  Mount  Unicorn, 
1;  Porcupine  Flat,  2;  Tuolumne  Meadows,  30);^"  Zonoda  Meadow    (Inyo 
County),  1." 
Nevada:  Near  Bijou,  Calif,,  3. 

CITELLUS  BELDINGI  OREGONUS   (Mereiam) 

Oregon  Ground  Squirrel 

Spermophilus  oregonus  Merriam,  Biol.  Soc.  Wash.  Proc.  12:  69,  Mar.  24,  1898. 
iCitellus}  oregonus  Trouessart,  Cat  Mamm.,  Sup.,  p.  339,  1904. 

Type. — Collected  in  Swan  Lake  Valley,  Klamath  Basin,  Oreg., 
June  12,  1897,  by  Vernon  Bailey;  female  adult,  skin  and  skull,  no. 
89177,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig.  no. 
6005). 

Range. — Eastern  Oregon,  northeastern  California,  southwestern 
Idaho,  and  northern  Nevada ;  north  to  Heppner  and  Elgin,  Oreg. ; 
east  to  Cassia  County,  Idaho,  and  Kuby  Valley,  Nev.;  south  to 
Plumas  County,  Calif.,  and  Ruby  Valley,  Nev.;  west  to  Klamath 
Lake,  Oreg.,  and  Goose  Nest  Mountain,  Calif,  (fig.  6).  Zonal  range: 
Upper  Sonoran  and  Transition. 

External  characters. — Similar  to  G.  h.  heldingi,  but  averaging 
slightly  smaller;  upper  parts  paler  and  more  grayish,  usually  with- 
out a  distinct  reddish  tone,  and  never  with  a  well-defined  band  of 
reddish  brown;  similar  to  G.  richardsonii  elegans.,  but  tail  shorter 
and  much  darker  (more  reddish)  beneath;  coloration  above  usually 
darker  and  more  reddish  (less  yellowish  or  buffy),  with  less  indica- 
tion of  mottling.  Compared  with  G.  armatus:  Closely  similar  in 
size  and  coloration,  but  dorsal  region  paler,  the  rump  and  thighs 
more  grayish  (less  tawny) ;  tail  reddish  rather  than  grayish  below, 
the  bordering  hairs  more  grayish  (less  buffy). 

Granial  characters. — Skull  similar  to  that  of  heldingi.,  but  averag- 
ing slightly  smaller  and  relatively  narrower  interorbitally.  Com- 
pared with  elegant:  Skull  relatively  longer  and  narrower;  zygomata 
weaker  and  more  contracted  anteriorly;  auditory  meatus  shorter. 

Golor. — Upper  parts  smolie  gray  or  pale  smoke  gray,  more  or  less 
washed  on  the  back  with  sayal  brown,  mikado  brown,  cinnamon,  or 
light  pinkish  cinnamon;  front  of  face  with  a  patch  of  pinkish  cin- 
namon or  pinkish  buff;  under  parts  and  sides  washed  with  pinkish 
buff,  the  under  fur  on  belly  dusky  neutral  gray;  feet  pinkish  buff; 
tail  above,  cinnamon  or  sayal  brown  mixed  with  smoke  gray  at  base 
and  heavily  shaded  with  black  on  distal  half;  tail  beneath,  hazel, 
bordered  with  black  and  edged  with  pale  tilleul  buff. 

Molt. — Only  a  very  few  specimens  in  the  large  series  examined 
show  definite  indications  of  molt;  two  adults  (male  and  female) 
from  Howard,  Oreg.,  June  16  and  18,  apparently  are  acquiring  new 
pelage,  the  new  hairs  coming  in  irregularly  over  the  whole  back.  A 
female  from  the  Ruby  Mountains,  Nev.,  June  20,  is  in  a  worn  gray- 
ish pelage,  with  a  patch  of  fresh,  reddish  pelage  coming  in  on  the 
fore  back. 

Measurements. — Average  of  10  adult  males  from  southwestern  Oregon  and 
northeastern  California  (Fort  Klamath,  Po  Valley,  Burns,  Snsanville,  Tule 
Lake)  :  Total  length,  271.5   (254-300)  ;  tail  vertebrae,  G3.8   (55-76)  ;  hind  foot, 


«Mus.   Vert.   Zool. 
"Cleveland  Mus.  Nat.  Hist. 
**Ten  In  Mub.  Vert.  Zool. 


84  NORTH  AMERICAN  FAUNA  [No.  56 

43  (41-45)  ;  average  of  8  adult  females  from  southern  Oregon  and  northern 
California:  276;  67;  42.7.  Skull:  Average  of  8  adult  males  from  southwest- 
ern Oregon  and  northern  California  (Fort  Klamath,  Tule  Lake,  Susanville, 
Madeline  Divide)  :  Greatest  length,  45  (43.2^-46.2)  ;  palatilar  length,  21.8 
(20.5-23)  ;  zygomatic  breadth,  28.9  (28.1-30.1)  ;  cranial  breadth,  20.2  (19.8- 
20.6)  ;  interorbital  breadth,  10.1  (9.2-10.7)  ;  postorbital  constriction,  11.7 
(10.7-12.3)  ;  length  of  nasals,  16.9  (16-18.2)  ;  maxillary- tooth  row,  9.4  (9-10.1)  ; 
average  of  8  females  from  same  region :  Greatest  length,  43.1  (41.3—44)  ; 
palatilar  length,  20.8  (19.8-21.5)  ;  zj'gomatic  breadth,  27.8  (24.8-29.8)  ;  cranial 
breadth,  19  (18.2-19.5)  ;  interorbital  breadth,  9.5  (9-10)  ;  postorbital  constric- 
tion, 11.1  (10.4-12)  ;  length  of  nasals,  16.1  (15-17)  ;  maxillary  tooth  row, 
9   (8.6-9.3). 

Weight. — Two  specimens  weighed  by  Vernon  Bailey  registered  1  pound  each ; 
one  of  these  was  recorded  as  very  fat.  Grinnell,  Dixon,  and  Linsdale  (1930, 
p.  483)  record  six  individuals  as  weighing  respectively,  212,  223,  230,  250,  260, 
and  260  g.  Grinnell  and  Dixon  (1918,  p.  652)  give  the  average  weight  of  6 
adult  females  as  302  g  (267-365.8). 

ReTnarks. — The  Oregon  ground  squirrel  is  abundant  and  widely 
distributed  in  the  Great  Basin.  It  is  closely  related  to  beldingi, 
and  although  the  ranges  of  the  two,  so  far  as  known,  are  not  actually 
contiguous,  5^et  the  two  forms  intergrade  completely  in  both  the  skin 
and  sijull  characters.  In  fact,  there  are  numerous  specimens  in  both 
series  that  are  so  near  like  certain  individuals  of  the  other  race  as  to 
be  practically  indistinguishable.  The  distinguishing  characters, 
however,  are  on  the  average  well  marked.  The  present  race  is 
known  from  specimens  as  far  south  in  California  as  Prattville,  and 
its  presence  has  been  reported  at  Red  Clover  and  Mohawk,  in  Plumas 
County,  whereas  heldingi  is  known  no  farther  north  than  Independ- 
ence Lake,  on  the  line  between  Sierra  and  Nevada  Counties,  approxi- 
mately 25  miles  southeast  of  Mohawk. 

^Specimens  examined, — Total  number,  405,  as  follows: 

California:  Alturas  (10  miles  southwest,  Modoc  County),  7;*'  Bald  Mountain 
(8  miles  south,  Shasta  County),  13;  Bieber  (Lassen  County),  3;  Big  Mead- 
ows (10  miles  west,  Plumas  County),  !;■"  Bull  Meadow  (Siskiyou  County, 
northeast  of  Goose  Nest  Mountain),  1;^°  Bunchgrass  Spring  (Lassen 
County),  2;  Eagle  Lake,  1;  Feather  River  (North  Fork,  18  miles  east  of 
Warner  Creek),  1;  Goose  Lake,  3;  Goose  Lake  Meadows  (near  Davis 
Creek,  Modoc  County),  2;^'  Goose  Nest  Mountain  (Siskiyou  County),  1;" 
Grass  Lake  (Siskiyou  County),  6;*®  Hayden  Hill  (Lassen  County),  1; 
Horse  Lake,  7:  Lower  Klamath  Lake,  1;  Macdoel  (Siskiyou  County),  24;*' 
Madeline  Divide,  5;  Madeline  Plains,  1;  Mount  Hebron  (Siskiyou  County), 
10;  Mount  Lassen  (probably  near  Black  Butte),  6;  Petes  Valley  (Lassen 
County),  1;  Pine  Creek  (Lassen  County),  1;  Pit  River  (North  Fork),  4; 
Pit  River  (South  Fork),  3;^'  Prattville  (12  miles  northeast),  4;  Sugar  Hill 
(Modoc  County),  4;"  Susan  River  (Lassen  County),  5;  Susanville,  6; 
Termo  (Lassen  County),  1;^^  Tule  Lake,  4;  Tuledad  Canyon  (northeastern 
corner  Lassen  County),  1;  Warner  Mountains,  6;  Westwood  (15  miles 
west,  Lassen  County),  1. 

Idaho:  Elba  (Cassia  County),  l;**  Hollister  (Twin  Falls  County),  1 ;  *■  Malta 
(Cassia  County),  1;^'  Mount  Harrison  (Cassia  County),  1;*"  Riddle  (15 
miles  southeast,  Owyhee  County),  1;  Silver  City,  8;  Sinker  Creek  (Owyhee 
County),  25. 

Nevada:  Badger  (20  miles  northwest  of  Summit  Lake,  Humboldt  County),  4; 
Calico  Mountain  (northeastern  Humboldt  County),  2;  Halleck  (Elko 
County),  1;  Massacre  Creek  (Washoe  County),  1;**  Mountain  City  (Elko 
County),  12;  Pine  Forest  Mountains,  12;"  Ruby  Moimtains,  1;  Ruby 
Valley,  10. 

Oregon:  Austin  (Grant  County),  2;  Baker  (10  miles  north),  3;"  Barnes  (Crook 
County),  3;"  Bear  Creek  (15  miles  northwest  of  Dayville,  Grant  County), 
1;**  Beech  Creek   (Grant  County),  2;  Beulah    (Malheur  County),  13;  Bu- 

^=Ten  in  Mus.  Vert.  Zool. 

*«Mus.  Vert.  Zool. 

^  Univ.  Michigan  Mus.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  §5 

chanan  (Harney  County),  6;  Buck  Creek  (Crook  County),  1;  Burns,  2; 
Camas  Prairie,  east  of  Lakeview,  5;*^  Cedar  Mountains,  1;  Diamond  (Har- 
ney County),  5;  Disaster  Peak  (Malheur  County),  1;  Drewsey  (Harney 
County),  1;  Elgin,  6;  Fort  Klamath,  23;  Harney  (10  miles  north),  4; 
Haycreek  (Jefferson  County),  13;  Heppner,  15;  Home  (Baker  County), 
10;  Howard  (Crook  County),  4;  Jordan  Valley  (Malheur  County),  5; 
Joseph  (Wallowa  County),  7;  Klamath  Falls,  3;  Lakeview,  1;  Lone  Rock 
(6  miles  east,  Gilliam  County),  1;  Lost  River,  Klamath  Basin,  1;  Mahog- 
any Mountain  (Malheur  County),  3;  Malheur  County,  near  McDermitt, 
Nev.,  3;  Malheur  Lake,  1;  Maury  Mountains  (Crook  County),  1;  Meacham 
(10  miles  south,  Umatilla  County),  1;  Mount  Vernon  (Grant  County),  2; 
Mount  Warner  (=Hart  Mountain,  Lake  County),  2;  Narrows  (Harney 
County),  4;  Po  Valley  (Lost  River,  Klamath  County),  1;  Prineville,  7; 
Rattlesnake  Creek  (at  head,  Malheur  County),  1;  Rockville  (Malheur 
County),  1;  Shirk  (Harney  County),  1;  Steens  Mountains,  13;  Swan  Lake 
Valley  (Klamath  County),  2;  Telocaset  (Union  County),  2;  Twickenham 
(Wheeler  County),  2;  White  Horse  Creek   (Harney  County),  1. 

CITELLUS  PARRYH  GROUP 

CITELLUS  COLUMBIANUS   (Ord) 
[Synonymy  under  subspecies] 

SpecifiG  characters. — Larger  than  O.  richardsonii  or  C.  armatus; 
hind  foot,  48-58  mm ;  tail,  80-116 ;  skull  length,  49.5-57.  Skull  rela- 
tively longer  than  that  of  richardsonii.,  the  zygomata  less  widely  ex- 
panded posteriorly;  dorsal  outline  much  flatter,  the  highest  point 
behind  the  postorbital  processes,  the  rostrum  not  sharply  depressed; 
interorbital  region  relatively  broad  and  flat,  the  supraorbital  margins 
not  elevated  or  thickened;  rostrum  and  nasals  longer;  upper  tooth 
rows  nearly  parallel;  audital  bullae  large  but  not  greatly  elevated; 
meatus  slightly  produced. 

Color. — Nose  and  face  tawny  or  hazel;  occiput,  nape,  and 
sides  of  neck  smoke  gray;  upper  parts  cinnamon  buff  or  sayal 
brown,  shaded  with  fuscous  and  in  winter  with  smoke  gray;  hmd 
legs  and  feet  tawny  or  hazel;  front  feet  ochraceous  buff;  tail  gray 
or  tawny ;  under  parts  ochraceous  buff  or  tawny. 

CITELLUS  COLUMBIANUS  COLUMBIANUS    (Ord) 

Columbian  Ground  Squirrel 

(Pis.  4;  24,  A;  29,  A) 

Arctomys    columUanus    Ord,    Guthrie's    Geography    (2nd    Amer.    ed.),    2:292 

(description,  p.  303),  1815. 
Anisonyx  hraohiura  Raflnesque,  Amer.  Monthly  Mag.  2 :  45,  1817. 
Arctomys  brachyura  Hnrlan,  Fauna  Americana,  p.  304,  1825. 
Arctomys  brachyurus  Richardson,  Fauna  Boreali-Americana,  p.  151,  1S29. 
Arctomys  parryi  var.  j8,  erythrofiluteia  Richardson,  Fauna  Boreali-Americana, 

p.  161,  1829  ("Rocky  Mountains,  near  the  sources  of  the  Elk  River"=Wolf 

Plain,  30  miles  west  of  Rock  Lake,  Alberta).** 
[Spermophihis  parryi]  var.  erythrogluteia  Allen,  Boston  Soc.  Nat.  Hist.  Proc. 

16:  292,  1874. 
Spermophilvs  empetra  var.  erythroglutaeus  Allen,  Monog.  North  Amer.  Roden- 

tia,  p.  839,  1877   (part). 
Spermophilns  rolnmhiavufi  Merriam,  North  Amer.  Fauna  5:  39,  1891. 
Citellus  colnmbianuH  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  19:536,  1903. 
Citellus  colnmbinnvs  albertae  Allen,  Amer.  Mus.  Nat.  Hist.  BuU.  19 :  537,  1903 

(Canadian  National  Park,  Alberta). 
CUellvs  (Colobotis)  columbianus  Preble,  North  Amer.  Fauna  27:  1G4,  1908. 


*'  narnegie  Mus. 

»o  See  remarks,  p.  88. 


86 


NORTH  AMERICAN  FAUNA 


[No.  56 


Type. — None  designated ;  original  description  based  on  Lewis  and 
Clark's  description  of  animals  taken  by  them  on  a  camas  prairie 
between  the  forks  of  the  Clearwater  and  Kooskooskie  Rivers,  Idaho, 
Range.— ^ook^  Mountain  region  of  western  Montana,  Idaho^ 
northeastern  Washington,  southeastern  British  Columbia,  and  west- 
ern Alberta;  also  the  plains  of  eastern  Washington  and  mountains 

of  east-central  Oregon 
(exclusive  of  the  Blue 
Mountains) ;  north  to 
the  headwaters  of 
South  Pine  Eiver, 
British  Columbia  (re- 
ported by  William 
Fox  from  this  locality 
and  from  mountains 
on  east  side  of  the 
lower  Parsnip  River) ; 
south  to  Craters  of  the 
Moon,  Butte  County, 
Idaho,  and  Harney 
County,  Oreg. ;  east  to 
Cutbank  and  Towns- 
end,  Mont.;  west  to 
Shuswap  and  Okana- 
gan  Lake,  British 
Columbia,  Oroville, 
Wash.,  and  Snow 
Mountain,  head  of 
Silver  Creek,  Harney 
County,  Oreg.  (fig. 
7).  Zonal  range: 
Canadian  and  Hud- 
sonian. 

External  charac- 
ters.— As  given  under 
specific  characters  (p. 
85)  ;     in     comparison 
with    C.   parryii  ple- 
sms,  upper  parts  not 
distinctly   spotted; 
sides  of  neck  gray  in- 
stead   of    buff;    hind 
feet  and  legs  darker 
(tawny   or   hazel   in- 
stead    of     cinnamon 
buff) ;  tail  edged  with 
white  instead  of  buff;  tail  averaging  longer  and  hind  feet  shorter. 
Cranial  characters. — As  given  (p.  85)  in  comparison  with  0.  rich- 
ardsonii   richardsonii.      Compared    with   plesius:    Skull   averaging 
smaller  and  relatively  narrower,  the  superior  outline  flatter   (less 
convex);  rostrum  longer  and  narrower;  supraorbital  shelf  not  ele- 
vated; palate  longer,  its  posterior  border  considerably  behind  plane 
of  last  molars;  posterior  loph  of  m^  low  and  sometimes  discontinuous. 
Color. — Summer  pelage:  Nose  and  front  of  face  tawny  or  hazel; 


Figure  7. — Distribution  of  the  subspecies  of  Citellus  colum- 
bianus:  1,  C.  o.  columhianus ;  2,  G.  c.  ruficaudus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  §7 

crown  mixed  cinnamon  buff  and  smoke  gray;  occiput,  nape,  and 
sides  of  neck  pale  smoke  gray;  eye  ring  pale  buff;  ears  hair  brown 
on  outer  surface,  buffy  or  tawny  on  inner  surface;  general  tone  of 
upper  parts  cinnamon  buff  or  sayal  brown,  more  or  less  shaded  with 
the  darker  color  of  the  under  fur,  which  is  fuscous  or  hair  brown; 
sides  washed  with  grayish  or  bufl'y  v\'hite;  under  parts  cinnamon 
buff  or  ochraceous  buff;  front  legs  and  feet  ochraceous  buff;  hind 
feet  ochraceous  tawny,  the  thighs  hazel;  tail  above,  black,  rather 
heavily  overlaid  with  grayish  white  and  sparingly  sprinkled  vrith 
cinnamon  buff  or  tawny;  tail  beneath,  mixed  fuscous  black  and 
grayish  white.  Winter  pelage  (March  and  April)  :  Similar  to  the 
summer  pelage  but  upper  parts  more  heavily  sprinkled  with  grayish. 

Variation. — Two  albinistic  juvenile  individuals  were  taken  at  Pull- 
man, Wash.,  May  10,  1906;  Svihla  (1933,  p.  78)  reports  seeing  three 
albino  individuals  there  in  1933. 

Molt. — The  annual  molt  occurs  in  June  or  July.  A  female  taken 
at  Ketchum,  Idaho,  June  6,  is  in  a  badly  worn  pelage,  with  new  hair 
appearing  on  the  forehead;  another  female  (subad.)  from  Columbia 
Falls,  Mont..  June  27,  shows  new  pelage  covering  the  head  and  me- 
dian dorsal  region,  nearly  to  the  rump ;  an  adult  female  from  Nelson, 
British  Columbia,  July  18,  shows  a  patch  of  fresh  summer  pelage 
on  the  middle  of  the  back;  an  adult  female  from  Piegan  Pass, 
Mont.,  is  in  a  much  worn  pelage,  with  new  hair  appearing  on  the 
head  and  nape;  a  juvenile  from  ISilver,  Mont.,  June  26,  Avas  acquiring 
a  new  pelage  in  patches  on  the  head  and  back.  In  the  large  series 
examined  no  evidence  has  been  found  that  would  indicate  a  molt 
in  the  autumn. 

Measurements. — Average  of  12  adults  (G  males,  6  females)  from  Idaho: 
Total  length,  349.7  (327-377)  ;  tall  vertebrae,  100.5  (83-116)  ;  hind  foot,  51.2 
(48-55).  Skull:  Average  of  10  adult  males  from  Idaho:  Greatest  length,  51.7 
(50-56)  ;  palatilar  length,  25.1  (24-27)  ;  zygomatic  breadth,  31.8  (30.5-33.8)  ; 
cranial  breadth,  20.8  (19.6-21.8)  ;  interorbital  breadth,  10.6  (9.0-12)  ;  post- 
orbital  constriction,  11.3  (10.4-12.5)  ;  length  of  nasals,  19.4  (1&-21.4)  ;  maxil- 
lary tooth  row,  10.9  (10.1-11.8).  Average  of  7  adult  femal(>s  from  Idaho: 
Greatest  length,  50.7  (49.5-51.9)  ;  palatilar  length,  24.8  (23-26)  ;  zygomatic 
l>readth,  32.2  (31.6-33.6)  ;  cranial  breadth.  21  (20.5-21.4)  ;  interorbital  breadth, 
11.2  (10.2-12)  ;  postorbital  constriction,  12  (11.4-12.2)  ;  length  of  nasals,  18.7 
(18-19.4)  ;  maxillary  tooth  row,  11   (10.4-11.6).. 

Weight. — Shaw  (1926a,  p.  137)  gives  the  weights  of  two  males  taken  in  late 
July  as  589  and  830  g,  respectively ;  eight  males  taken  from  the  hibernation  den 
at  time  of  awakening  averaged  492  g  (43.1-571)  ;  two  males  running  at  large  on 
March  10,  after  hibernation,  weighed  respectively,  341  and  375  g.  Two  females 
taken  when  going  into  hibernation  weighed  respectivelv,  414  and  500  g  (Shaw, 
19251,  p.  764). 

Remarks. — The  Columbian  ground  squirrel  is  quite  distinct  from 
any  other  species  and  its  range  apparently  does  not  meet  that  of 
C.  parryii  plesius  in  British  Columbia.  The  latter  reaches  its  south- 
ern limit  in  the  vicinity  of  Tatletuey  Lake,  and  colnmhianus  ranges 
no  farther  nortli  than  the  mountains  lying  east  of  Parsnip  River  and 
south  of  Peace  River,  tlnis  leaving  a  gap  of  160  miles  or  more  un- 
occupied by  ground  squirrels  of  this  group.  In  Montana  and  south- 
ern Idaho,  this  species  is  apparently  extending  its  range  eastward 
and  southward,  doubtless  attracted  from  its  natural  home  in  the 
mountain  meadows  to  the  cultivated  fields  in  the  valleys. 

The  form  occupying  the  Blue  Mountains  region  of  Oregon  and 
Wasliington  is  recognized  as  a  subspecies,  but  nearly  typical  colum- 
hiccnus  occurs  in  the  low  mountains  south  of  this  area  and  probably 


88  NORTH  AMERICAN  FAUNA  [No.  56 

in  all  the  surrounding  foothills.  Two  adult  specimens  from  moun- 
tains 10  miles  north  of  Harney  and  3  miles  from  Ironsides,  Oreg., 
are  intermediate,  agreeing  in  color  with  columbianus  and  in  skull 
characters  with  G.  c.  ruficaudus. 

Although  discovered  by  Lewis  and  Clark  in  their  epochal  journey 
across  the  continent  in  1804-6  and  described  by  Ord  in  1815,  this 
species  was  very  imperfectly  known  for  many  years,  and  the  name 
columbianus  was  misapplied  to  the  plateau  prairie  dog  {Gynomys 
gunnisoni) . 

Richardson,  1829,  named  a  ground  squirrel  procured  by  Drummond 
in  the  Canadian  Rockies  as  a  variety  of  the  Parry  ground  squirrel — 
Arctomys  parryi  var.  fi,  erythrogluteia.  Allen  (1877)  adopted  Rich- 
ardson's name,  listing  under  it  two  specimens  from  the  head  of 
Flathead  River  and  two  from  Kootenay  River — both  localities  in 
southeastern  British  Columbia.  Merriam  (1891,  p.  39),  having  pro- 
cured specimens  from  the  vicinity  of  the  type  locality  of  colum- 
bianus,  cleared  up  the  situation,  showing  that  the  "burrowing  squir- 
rel" of  Lewis  and  Clark  was  actually  a  ground  squirrel,  and  that  the 
names  columbianus  and  erythrogluteia  referred  to  the  same  species- 
Allen,  however,  in  1903,  revived  the  name  erythrogluteia  and  ap- 
plied it  to  the  form  of  parryii  occurring  on  the  head  of  Telegraph 
Creek  and  Sheslay  River,  British  Columbia,  which  he  recognized 
as  distinct  from  columbianus  and  wliich  had  been  named  plesius  by 
Osgood  in  1900.  This  assignment  of  erythrogluteia  was  made  on  the 
assumption  that  the  type  locality — Elk  River,  Rocky  Mountains — 
is  in  latitude  57°  N.,  as  stated  by  Richardson  in  the  original  descrip- 
tion, and  therefore  not  far  from  the  Telegraph  Creek  region.  This 
however,  was  an  error,  for  as  Preble  has  shown  (1908,  p.  164),  the 
"Elk  River"  of  Richardson  is  the  Athabaska,  and  its  sources  are 
between  52°  and  54°  N.  Richardson's  species — erythrogluteia — was 
based  on  specimens  collected  by  Thomas  Drummond  and  the  type 
locality  is  determined  by  a  reading  of  Drummond's  sketch  of  his 
journey  published  in  Hooker's  Botanical  Miscellany  (1830,  p.  178). 
On  page  212  of  this  publication  he  speaks  of  finding  Arctomys  parryi 
abundant  "on  the  mountains  near  the  Wolf's  Plain"  and  states  that 
specimens  were  "brought  home."  On  page  199  he  gives  the  location 
of  Wolf  Plain  as  "about  30  miles  west  from  Lac-la-Pierre"  (  =  Rock 
Lake).  Rock  Lake  is  about  25  miles  northwest  of  the  lower  end  of 
Jasper  Lake.  This  would  fix  the  type  locality  of  erythrogluteia 
as  near  the  headwaters  of  Sulphur  River,  a  branch  of  Smoky  River. 
Specimens  of  this  animal  were  taken  by  J.  Alden  Loring  in  1895, 
on  Smoky  River,  a  short  distance  from  this  locality,  and,  as  already 
stated,  they  prove  to  be  indistinguishable  from  typical  columbianus. 
Examination  of  a  series  from  Canadian  National  Park  that  formed 
the  basis  of  Allen's  ''^albertae''''  shows  their  characters  to  be  too  slight 
and  inconstant  to  admit  of  recognition  in  nomenclature.  The  skulls 
average  slightly  larger  and  flatter  than  those  of  typical  columbianus 
and  the  jugal  averages  broader,  but  these  characters  are  not  constant 
in  the  series  of  10  skulls  examined;  the  shape  of  the  antorbital 
foramen  varies  from  triangular  to  circular. 


19381  REVISION  OF  THE  GROUND  SQUIRRELS  39 

Specimens  examhied. — Total  number,  351,  as  follows: 

Alberta:  Banff,  6;  [Rocky  Mountains]  75  miles  southwest  of  Calgary,  1;" 
Canadian  National  Park,  3;  '"'■  Crows  Nest  (Livingstone  River),  1;  "  Crows- 
nest  Pass,  1;'^  Hay  River  (near  head),  1;  Henry  House  (25  miles  west), 
1 ;  Jasper  Park,  13  ; '' ''  Mount  Forgetmenot,  4  :  ='  Ptarmigan  Lake,  3 ;  ^' 
Silver  City,  2;  °-  Smoky  Valley  (50  miles  north  of  Jasper  House),  7;  Sulphur 
River  (upper),  2;  Waterton  Lake  Park,  5.°* 

British  Columbia:  Barkerville,  1;''  Cascade,  G;""  Cranbrook,  9;''  Deer  Park, 
2  ; '-  Fernie.  1 ;  ^  Indianpoint  Lake,  2 ;  ^'  Midway,  4 ;  ^-  Mount  Queest,  2  ;  "^ 
Nelson,  12 ;  Okanagan,  4  ;  "  =^  Okanagan  Falls,  2  ;  "=  Shuswap,  4 ;  '"^  Shuswap 
River  (headwaters.  Gold  Range),  1;  Spillimachene  River,  3.^ 

Idaho:  Bald  Mountain  Ranger  Station  (10  miles  south  of  Idaho  City),  2;  Bitter- 
root  Mountains,  1;'^  Coeur  d'Alene,  9;  Edna  (15  miles  northeast  of  Idaho 
City),  4;  Forney,  2;  Fort  Sherman  (near  Coeur  d'Alene),  2;  Galena  (30 
miles  north  of  Ketchum),  9;  Goodrich  (Adams  County),  3;  Idaho  City, 
5;  Ketchum,  17;  Lardo  (Valley  County),  1;  McKinuis  (7  miles  east, 
Shoshone  County),  1;^  Moscow,  38;  Mullan,  5;  New  Meadows  (Adams 
County),  2;  Nez  Perce,  2;  Packer  Meadow  (south  of  Lolo  Hot  Springs), 
4;  Seven  Devils  Mountains,  2;  Shafer  Butte  (Boise  County),  6;^  Tamarack 
(Adams  County),  1;   Troy,  1;"  Warren    (Idaho  County),   1. 

Montana:  Bass  Creek  (northwest  of  Stevensville),  1;  Carroll  (Deerlodge 
County),  6;  Columbia  Falls,  8;  Corvallis,  4;  Deerlodge  County,  1;^^  Flat- 
head Lake  (north  end),  2;  Flathead  River  (at  International  Boundary), 
2;  Florence,  7:  Gibbon  Pass  (Beaverhead  County),  8;^'  Hamilton,  3j" 
Helena,  3;  Kalispell,  4;  Lolo,  3;  McDermott  Lake,  3;  Nyack  (Flathead 
County),  4:  Piegan  Pass  (Glacier  National  Park),  1;  Prospect  Creek  (near 
Thompson  Falls),  1;  St.  Marj',  2;"  Silver  (  =  Saltese,  Missoula  CoimtyJ, 
4;  Sula,  1;  Thompson  Falls,  1;  Tobacco  Plains  (=Gateway,  Lincoln 
County),  1;  Willow  Creek  (7  miles  east  of  Corvallis),  1;  Wisdom  (20 
miles  north,  Beaverhead  County),  4." 

Oregon:  Harney  (10  miles  north),  4;  Ironside  (Malheur  County),  3;"  Straw- 
berry Mountains,  3. 

Washington:  Calispell  Lake  (Pend  Oreille  County),  1;  Calispell  Peak,  2; 
Cheney,  2;  Colfax,  1;  Colville,  16;  Gifford  (Stevens  County),  2;  Loon  Lake 
(Stevens  County),  6;"  Pullman,  4;  Spokane,  8;  Sullivan  Lake  (Pend 
Oreille  County),  2;  Williams  Lake  (Spokane  County),  1." 

CITELLUS  COLUMBIANUS  RUFICAUDUS  Howet.l 

Blue  Mountains  Gbound  Squiekel 

Citellus  columUanus  ruficaudiis  Howell,  Biol.  Soc.  Wash.  Proc.  41  :  212,  Dec.  18, 
1928. 

Type. — Collected  at  Wallowa  Lake,  Wallowa  County,  Oreg.,  April 
13,  1919,  by  George  G.  Cantwell;  female  adult,  skin  and  skull,  no. 
231942,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig.  no. 
1093). 

Range. — The  Blue  Mountains  region  of  Oregon  and  Washington, 
from  Prescott  and  Dayton,  Wash.,  south  to  Dixie  Butte,  Grant 
Comity,  Oreg. ;  east  to  the  AVallowa  Mountains,  Oreg.  (fig.  7).  Zonal 
range:  Canadian  and  Hudsonian. 

External  charaGters. — Similar  to  C.  c.  columbianus.  but  upper  side 
of  tail  tawny  (not  gray) ;  sides  of  face  and  usually  the  throat  a 
deeper  shade  of  tawny ;  legs  and  feet  darker ;  hind  feet  longer. 

Cranial  characters. — Skull  similar  to  that  of  columhianus,^  but 
larger  and  relatively  broader;  zygomata  more  heavily  built,  the  jugal 
wider. 


"^lAmor.  JIus.  Nat.  Hist. 

"^2  Nat.  Mu.s.  Canada. 

C3  Provincial  Mus.,  Victoria,  B.  C. 

""  Univ.  MichiRan  Mus.  Zool. 

^'  iJonalfl  R.  Dicltey  coll. 

^  Cleveland  Mus.  Nat.  Hist. 

"Montana  State  College. 


90  NORTH  AMERICAN  FAUNA  [No.  56 

Color. — Summer  pelage  (May  28)  :  Forehead  and  face  hazel;  sides 
of  nose  and  throat  ochraceous  buff  or  ochraceous  tawny;  eye  ring 
broad,  pinkish  buff;  occiput  cinnamon  buff,  more  or  less  mixed  with 
smoke  gray  and  fuscous;  sides  of  neck  (beneath  eyes)  and  an  in- 
distinct band  across  nape,  smoke  gray;  dorsum  cinnamon  buff 
grizzled  with  fuscous;  sides  smoke  gray,  mixed  w^ith  fuscous;  front 
legs  and  feet  tawny  or  ochraceous  tawny;  hind  feet  deep  tawny,  the 
thighs  russet ;  tail  above,  deep  tawny,  the  hairs  banded  subterminally 
with  fuscous  black  and  cinnamon  buff ;  tail  beneath,  mixed  tawny  and 
smoke  gray;  under  parts  clay  color  or  cimiamon  buff,  shading  to 
ochraceous  tawny  on  throat.  Winter  pelage  (April  13)  :  Similar  to 
the  summer  pelage,  but  upper  parts  pale  smoke  gray,  mixed  with 
pinkish  buff'  and  grizzled  with  fuscous;  feet  slightly  paler  tawny. 

Molt. — A  female  specimen  from  the  Blue  Mountains,  Wash.  (3,000 
feet  altitude),  June  16,  is  in  badly  worn  condition,  with  new  hair 
appearing  on  the  head  and  nape. 

Measurements. — ^Average  of  10  adults  (8  males,  2  females)  from  the  Wallowa 
Mountains,  Enterprise.  Elgin,  and  Bourne,  Oreg. :  Total  length,  369.6  (340-410)  ; 
tail  vertebrae,  100.7  (80-115);  hind  foot,  54.2  (51-58).  ^kull:  Average  of  8 
males  (ad.  and  subad.)  from  same  localities:  Greatest  length,  54.2  (51.5-57)  ; 
palatilar  length,  26.6  (24..5-28)  ;  zygomatic  breadth,  34.1  (33.2-.35.6)  ;  cranial 
breadth,  21.9  (21.5-22.4)  ;  interorbital  breadth,  12.4  (11.1-14.3)  ;  postorbital 
constriction,  11.9  (10.5-12.6)  ;  length  of  nasals,  19.8  (18.8-20.3)  ;  maxillary  tooth 
ro-w,  11.4  (10.5-12.4).  Average  of  4  females  from  same  region:  Greatest  length. 
52.9  (50.7-54.7)  ;  palatilar  length,  25.7  (24.5-27.5)  ;  zygomatic  breadth,  33.3 
(31.2-34.6)  :  cranial  breadth,  21.3  (20.4-21.7)  ;  interorbital  breadth,  12.5  (11.5- 
13.2)  ;  postorbital  constriction,  12.1  (11.9-12.3)  ;  length  of  nasals,  19.3  (18.7- 
19.7)  ;  maxillary  tooth  row,  11.3  (11-11.8). 

Remarhs. — This  race  is  restricted  to  the  Blue  Mountains  region  of 
northeastern  Oregon  and  southeastern  Washington;  it  intergrades 
with  coluTnbianus  in  the  Strawberry  Mountains  and  on  the  southern 
slopes  of  the  Burnt  River  Mountains,  Oreg. 

Specimens  examined. — Total  number,  69,  as  follows : 

Oregon:  Anthony  (6  miles  southwest  of  Cornucopia),  16;"^  Austin  (Grant 
County),  1;  Bourne  (Baker  County),  3;  Cornucopia  (Baker  County),  7; 
Dixie  Butte  (Grant  County),  6;  Elgin,  5;  Enterprise,  2;  Joseph,  1 :™ 
Meacham,  4 ;  "Wallowa  Lake,  7. 

Washington:  Anatone  (Asotin  County),  2;  Blue  Mountains  (21  miles  south- 
east of  Dayton),  4;  Dayton,  4;''  Prescott,  7.**'" 

CITELLUS  PARRTII    (Richardson) 
[Synonymy  under  subspecies] 

Specific  characters. — Size  medium  to  large;  hind  foot,  50-68  mm; 
tail,  77-138 ;  skull  length,  50.7-65.7.  Skull  heavily  built  and  angular, 
its  superior  outline  convex,  highest  at  plane  of  postorbital  processes ; 
the  rostrum  and  brain  case  moderately  depressed;  zygomata  broad 
and  heavy,  widely  spreading  and  strongly  twisted  from  the  vertical 
plane ;  postorbital  processes  heavy,  depressed,  directed  slightly  back- 
wards; supraorbital  shelf  thickened  and  elevated;  nasals  broad, 
ending  about  even  with  premaxillae;  antorbital  canal  large,  orbic- 
ular, with  a  pronounced  process  at  its  anterior  opening;  audital 
bullae  broad,  moderately  inflated,  the  meatus  tube  moderately  pro- 
duced; molariform  teeth  heavy,  the  anterior  upper  premolar   {p^) 


ssAmer.  Mus.  Nat.  Hist. 
"^  Univ.  Michigan  Mus.  Zool. 
««Mus.  Vert.  Zool. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


91 


one-third  to  nearly  one-half  of  p*;  i)osterior  loph  on  m^  well  de- 
veloped (but  lower  than  anterior  loph)  and  continuous  (not  broken 
by  a  sulcus  in  middle) ;  incisors  relatively  slender  and  projecting 
forward. 

Color. — Head  tawny  or  cinnamon;  rest  of  upper  parts  red- 
dish brown,  cinnamon,  or  fuscous,  more  or  less  abundantly  flecked 
with  rather  large  whitish  spots;  under  parts  ochraceous  tawny  to 
cinnamon  buff  in  summer  pelage,  ochraceous  buff  or  grayish  white  in 
winter;  sides  of  head  and  body  buff  or  tawny  in  summer,  becoming 
smoke  gray  in  winter;  feet  and  legs  tawny,  ochraceous  buff,  or  cin- 
namon; tail  above,  ochraceous  tawny,  cinnamon,  or  cinnamon  buff, 
more  or  less  mixed  with  fuscous  black ;  tail  beneath,  russet  or  tawny. 


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Figure  8. — Distribution  of  the  species  and  subspecies  of  the  Citellus  parryii  group :  1, 
C.  p.  parryii;  2,  C.  p.  banoice7inis ;  3,  C.  /'.  plesiusj  4,  C.  p.  abltisus ;  5,  C.  p.  nebulicola; 
6,  G.  kodiacenais ;  7,  O.  oagoodi;  8,  C.  p.  lyrattis. 

CITELLUS  PARRYII  PARRYII   (Richakdson) 

Fabry's  Ground  Squiebel 

Arctomys  parryii  Richardson,  Appendix  to  Parry's  Second  Voyage,  p.  316,  1825 

(1827). 
Spermophilus  parryii  Lesson,  Manuel  de  Manim.,  p.  244,  1827. 
Arctomys  {Spermophilus)  parry i  Richardson,  Fauna  Boreali-Amer.  1:  158,  1829. 
Arctomys  parry i  var.   phaeognatha  Richardson,    Fauna   Boreali-Amer.    1 :  161, 

1829  (Hudson  Bay). 
A[rctomys]  kennicottii  Ross,  Canad.  Nat.  &  Geol.  G:  434,  1861  (Fort  Good  Hope, 

Mackenzie). 
Spermophilus  empetra  Allen,  Monog.  North  Amer.  Rodentia,  p.  839,  1877   (not 

Mus  empetra  Pallas). 
Spermophilus  parryi  Preble,  North  Amer.  Fauna  22 :  46,  1902. 
Citellus  parryii  Miller  and  Rehn,  Boston  Soe.  Nat.  Hist.  Proc.  31 :  75,  1903. 
Citellus  (Colobotis)  parryi  kennicotti  Preble,  North  Amer.  Fauna  27:  162,  1908. 
Citellus   (Cololotis)    parryi  Preble,  in  Seton,  The  Arctic  Prairies,  app.   F.,  p. 

342    1911. 
Citellus  parryi  kennicottii,  Hall,  Calif.  Univ.  Pubs.,  Zool.  30 :  423,  1929. 

Type. — None  designated;  description  based  on  specimens  collected 
at  Five  Hawser  Bay,  Lyon  Inlet,  Melville  Peninsula,  Hudson  Bay, 
Canada. 

Range. — Barren  Grounds  of  northern  Canada  from  Melville  Penin- 
sula and  western  shores  of  Hudson  Bay  west  to  northwestern  Yukon 


92  '  NORTH  AMERICAN  FAUNA  [No.  56 

and  northeastern  Alaska ;  south  to  Rampart  House  on  Alaska- Yukon 
boundary,  Artillery  Lake,  Mackenzie,  and  a  point  about  25  miles 
south  of  Cape  Eskimo,  Hudson  Bay  ^^  (fig.  8).     Zonal  range:  Arctic. 

External  characteTS. — Size  large;  entire  head  (in  summer)  tawny 
or  russet;  upper  parts  brownish,  more  or  less  mixed  with  gray  and 
flecked  with  large,  irregular,  whitish  spots ;  tail  russet  beneath,  edged 
with  cinnam^on;  under  parts  tawny;  winter  pelage  much  paler  and 
more  whitish,  the  under  parts  ochraceous  buff  or  grayish  white. 

Cranial  characters. — As  given  under  specific  characters  (p.  90) ; 
skull  large,  equaling  that  of  G.  osgoodi;  much  larger  than  that  of 
G.  p.  plesius;  temporal  ridges  uniting  in  adults  to  form  a  prominent 
sagittal  crest. 

Color. — Summer  pelage  (Hudson  Bay,  25  miles  south  of  Cape 
Eskimo,  August)  :  Top  of  head  (nose  to  occiput)  russet  or  tawny; 
sides  of  nose  and  face  cinnamon  buff  or  ochraceous  buff;  eye  ring 
(often  indistinct)  pinkish  buff  or  cartridge  buff;  sides  of  neck 
tawny,  shaded  with  fuscous  black;  dorsum  russet  or  bister,  abun- 
dantly flecked  with  rather  large,  irregular  spots  of  creamy  white  or 
buffy  white;  front  and  hind  legs  tawny  or  ochraceous  tawny,  the 
feet  ochraceous  buff;  under  parts  ochraceous  tawny,  becoming  cin- 
namon buff  on  the  throat;  tail  above,  blackish,  shaded  on  proximal 
half  with  ochraceous  tawny  or  hair  brown  and  sparingly  edged  with 
ochraceous  tawny  or  avellaneous;  tail  beneath,  russet,  widely  bor- 
dered at  tip  with  blackish.  Winter  pelage  (Dolphin  and  Union 
Strait,  Arctic  coast.  May)  :  General  tone  of  upper  parts  pale  smoke 
gray,  sparingly  sprinkled  with  black  hairs  and  shaded  with  sayal 
brown  in  the  middle  of  the  back ;  top  of  head  and  face  cinnamon  or 
pinkish  cinnamon;  under  parts  pinkish  buff  or  ochraceous  buff; 
tail  above,  smoke  gray,  mixed  with  cinnamon  buff,  the  tip  blackish; 
legs  and  feet  pinkish  buff,  pinkish  cinnamon,  or  ochraceous  buff. 

Variation. — Several  young  specimens  from  Artillery  Lake, 
Mackenzie  (U.  S.  Natl.  Mus.  nos.  180894,  180895,  Aug.  ^6),  differ 
from  Hudso]!  Bay  specimens  taken  at  the  same  season  in  having 
the  back  of  a  grayish  tone,  produced  by  a  mixture  of  fuscous  and 
grayish  white.  An  adult  (no.  180922)  from  the  same  locality,  but 
without  date,  is  of  the  normal  brownish  color.  A  series  of  subadult 
specimens  from  Clinton  Golden  Lake  and  Thelon  River,  Mackenzie, 
taken  in  early  August,  are  in  worn  pelage  distinctly  paler  and 
more  grayish  tlian  the  August  specimens  from  the  coast  of  Hudson 
Bay.  An  adult  from  Gollinson  Point,  on  the  north  coast  of  Alaska 
(Sept.  30)  has  tlie  under  parts  grayish  white,  very  faintly  washed 
with  pale  pinkish  buff;  others  from  the  same  section  at  the  same 
season  have  the  under  parts  partly  white  and  partly  ochraceous 
buff.  Several  summer  specimens  from  Cape  FuUerton,  Hudson  Bay, 
have  the  head  and  sides  of  neck  heavily  washed  with  bay  or  chestnut 
and  others  from  the  northeast  coast  of  Alaska  have  a  less  intense 


81 A  specimen  in  the  National  Museum  of  Canada,  collected  by  Owen  O'Sullivan  and 
labeled  as  from  "Lat.  53°  N.,  Long.  83°  W."  indicates  a  southward  extension  of  the  ani- 
mal's range  to  a  point  on  the  west  side  of  James  Bay ;  Dr.  R.  M.  Anderson  has  kindly 
looked  up  the  records  of  O'SuUivan's  trip  (Canada  Geol.  Survey  Summary  Kept.,  190S, 
no.  1072,  1909,  p.  93)  and  he  finds  no  reason  to  doubt  that  the  specimen  was  taken  at 
the  point  indicated  by  the  label.  In  view  of  the  fact,  however,  that  other  explorers  have 
failed  to  find  any  evidence  of  the  occurrence  of  this  species  at  either  Fort  Churchill  or 
York  Factory,  the  record  from  James  Bay  is  most  surprising,  and  suggests  the  possibility 
of  error. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  93 

wash  on  the  head  and  a  broad  streak  of  chestnut  on  the  middle 
of  the  belly. 

Molt. — The  spring  molt  takes  place  chiefly  in  June  but  the  process 
is  clearly  shown  by  only  a  few  of  the  specimens  examined.  An  adult 
male  from  Firth  River,  Alaska- Yukon  boundary,  June  24,  1912, 
is  in  badly  worn  winter  pelage,  with  the  new  summer  pelage  showing 
in  patches  on  the  nape  and  back ;  another  adult  male  from  U  Creek, 
Alaska,  June  27,  shows  new  pelage  covering  the  head,  fore  legs  and 
portions  of  the  belly.  An  adult  female  from  Old  Fort  Good  JHope, 
June  27,  is  acquiring  a  fresh  pelage  of  a  grayish  tone  on  the  upper 
parts,  the  under  parts  apparently  in  complete  summer  pelage,  but 
the  tail  hairs  not  fully  renewed.  An  adult  female  from  Clinton 
Colden  Lake,  Mackenzie,  August  2,  is  in  greatly  worn  pelage,  with 
new  hair  of  a  grayish  tone  coming  in  on  the  shoulders,  and  patches 
of  new  buffy  hair  on  the  under  parts.  The  fall  molt  occurs  in 
September  or  October,  and  as  usual  in  this  genus,  the  change  is 
obscurely  indicated.  Two  specimens  from  Collinson  Point,  Alaska, 
taken  September  22  and  24,  1913,  show  the  winter  pelage  cover- 
ing the  head,  shoulders,  fore  back,  and  most  of  the  under  parts, 
the  moderately  worn  suimner  pelage  still  remaining  on  the  hinder 
back  and  on  the  middle  of  the  belly. 

Measurements. — Average  of  8  adult  males  from  the  Arctic  coast  of  Mack- 
enzie (Corouatiou  Gulf  to  Franklin  Bay)  :  Total  length,  443  (420-495)  ;  tail 
vertebrae,  124  (115-13G)  ;  hind  foot,  C5.6  (G3-68).  Average  of  5  adult  females 
from  same  localities:  Total  length,  414  (890-430)  ;  tail  vertebrae,  122.6  (9S- 
13S)  ;  hind  foot,  50.2  (57-61).  Average  of  9  adult  males  from  Aylmer  and 
Clinton  Colden  Lakes  and  near  Cape  Eskimo,  Mackenzie :  Total  length,  4U0 
(380-430);  tail  vertebrae,  125  (115-140);  hind  foot,  63.6  (60-66).  Skull: 
Average  of  6  adult  males  from  west  coast  of  Hudson  Bay  (Cape  Fullertou 
and  Cape  Eskimo)  and  Aylmer  and  Clinton  Colden  Lakes,  Mackenzie :  Greatest 
length,  60.9  (60-62.2)  ;  palatilar  length,  31.2  (30.3-32.5)  ;  zygomatic  breadth, 
402  (39.3-42)  ;  cranial  breadth,  24.7  (23.5-25.5)  ;  interorbital  breadth,  13.4 
(12.9-13.8)  ;  postorbital  constriction,  13.4  (12.7-14.1)  ;  length  of  nasals,  23.6 
(21.0-25.1);  maxillary  tooth  row,  13.6  (13.2-14.1).  Average  of  4  old  adult 
males  from  Dolphin  and  Union  Strait,  Arctic  coast :  Greatest  length,  64.3 
(63.3-65.7)  ;  palatilar  length,  33.2  (33-33.5)  ;  zygomatic  breadth,  42.8  (40.6- 
44.1)  ;  cranial  breadth,  25.4  (24.7-26.4)  ;  interorbital  breadth,  14.9  (14.3-15.6)  ; 
postorbital  constriction,  12.9  (12.4-13.3)  ;  length  of  nasals,  25  (23.7-25.9)  ; 
maxillary  tooth  row,  14.1  (13.7-14.3).  Average  of  6  adult  females  from  west 
coast  of  Hudson  Bay  and  interior  Mackenzie:  Greatest  length,  57.5  (55.4-59.5)  ; 
palatilar  length,  29.6  (20-30.5,  3  specimens);  zygomatic  breadth,  37.6  (35.8- 
39.4)  ;  cranial  breadth,  23.5  (22.8-24.2)  ;  interorbital  breadth,  12.9  (12.5-13.4)  ; 
postorbital  constriction,  134  (11.7-14.3);  length  of  nasals,  21.5  (20-22.9); 
maxillary  tooth  row,  13.3  (12.4-13.7).  Average  of  4  old  adult  females  from 
Arctic  coast  (Dolphin  and  Union  Strait  and  Coronation  Gulf)  ;  Grealest 
length,  61.2  (60.7-62.1);  palatilar  length,  31.9  (.31.5-32);  zygomatic  breadth, 
40.9  (40.5-41.5)  ;  cranial  breadth,  24.5  (24.2-24.9)  ;  interorbital  breadth,  13.6 
(12.0-14.4)  ;  postorbital  constriction,  13.1  (12.2-13.7)  ;  length  of  nasals,  23.4 
(23.2-24)  ;  maxillary  tooth  row,  13.8  (13.4-14.2). 

Weight.— K  male  taken  at  Collinson  Point,  Alaska,  September  9,  weighed 
2  pounds,  4  ounces ;  another  male  from  the  same  locality,  September  7,  weighed 
2  pounds,  8  ounces;  and  a  female  taken  there  October  2,  weighed  1  pound, 
9  ounces. 

Remarks. — Although  described  more  than  a  hundred  years  ago,  this 
large  ground  squirrel,  until  recently,  has  been  imperfectly  known 
and  poorly  represented  in  collections.  Even  now,  although  a  series 
of  over  100  specimens  has  been  brought  together,  there  is  a  lack  of 
material  in  unworn  summer  pelage,  which  fact  makes  it  difficult 
to  describe  the  pelage  variations.    The  species  exhibits  a  very  con- 


94  NORTH  AMERICAN  FAUNA  [No.  56 

siderable  amount  of  both  individual  and  seasonal  variation  and 
from  only  a  few  localities  are  there  unworn  specimens  illustrating 
both  the  summer  and  the  winter  pelages.  Specimens  in  fresh  winter 
pelage  are  lacking  from  Hudson  Bay  and  the  entire  region  east  of 
Coronation  Gulf.  A  series  from  Cape  Fullerton,  Hudson  Bay — some 
225  miles  southwest  of  the  type  locality — undoubtedly  represents 
the  typical  form.  These  are  without  date  of  capture  (excepting  one 
marked  October)  but  apparently  were  taken  in  late  summer  (August 
or  September) .  Most  of  them  show  considerable  wear.  Two  adults 
in  slightly  worn  summer  pelage  and  two  full  grown  young  of  the 
year  in  unworn  pelage  taken  near  Cape  Eskimo,  Hudson  Bay,  Aug- 
ust 10  and  11,  1900,  are  slightly  darker  above  than  the  average  of  the 
Cape  Fullerton  specimens,  the  back  less  strongly  flecked  with  whitish 
spots.  These  Cape  Eskimo  specimens,  however,  are  considered  typi- 
cal and  have  been  used  in  making  comparisons;  they  may  be  very 
closely  matched  in  a  large  series  taken  in  July  and  August  on  Firth 
Eiver,  northwestern  Yukon,  about  45  miles  from  the  Arctic  coast. 
The  skulls  of  these  Yukon  specimens  average  slightly  smaller  than 
the  series  from  Hudson  Bay  but  are  essentially  like  them  in  their 
characters. 

Variation  in  size  of  skull  is  extreme  in  this  species.  Eight  very 
old  specimens  (four  males,  four  females)  in  a  series  from  the  vicinity 
of  Coronation  Gulf,  Arctic  coast,  are  decidedly  larger  than  any 
others  examined.  Probably  this  excessive  size  is  due  to  the  age  of  the 
animals,  and  a  larger  series,  including  some  subadults,  would  doubt- 
less show  a  smaller  average.  Nine  adult  males  of  a  series  from  Firth 
River,  on  the  Alaska- Yukon  boundary  (which,  as  stated  above,  agree 
in  color  with  parity ii  from  Hudson  Bay)  average  slightly  smaller 
than  either  the  Hudson  Bay  series  or  those  from  the  Alaska  coast. 

The  disposition  of  the  name  kennicotfii,  proposed  by  Ross  in  1861 
is  made  difficult  by  the  lack  of  comparable  material  from  the  type 
locality,  which,  as  shown  by  Preble  (1908,  p.  162),  is  "the  lower 
Mackenzie  region",  in  the  vicinity  of  Old  Fort  Good  Hope  and 
Anderson  River.  Unfortunately,  there  are  available  only  three 
summer  specimens  from  this  section,  one  from  Old  Fort  Good  Hope, 
taken  June  27,  one  from  Lockhart  River,  without  date,  and  one  from 
Anderson  River,  August  1.  The  Anderson  River  specimen  is  an 
immature  individual  m  a  much  worn  pelage,  but  is  clearly  referable 
to  parryii,  the  under  parts  being  of  the  same  tawny  color ;  the  Lock- 
hart  River  specimen  is  in  a  worn  (summer?)  pelage,  with  very  indis- 
tinct spotting;  the  under  parts  and  sides  are  ochraceous  buff,  con- 
siderably paler  than  in  typical  parryii;  the  Fort  Good  Hope  speci- 
men was  apparently  acquiring  summer  pelage;  it  is  paler  on  the 
head,  tail,  sides,  and  under  parts  than  typical  pan^yii;  the  upper 
parts  are  of  a  uniform  brownish  gray  tone,  practically  without 
spotting;  possibly  this  individual,  which  in  size  and  cranial  char- 
acters agrees  with  parryii,  represents  approach  to  the  subspecies 
plesius^  which  occupies  the  mountainous  regions  west  of  the  Mac- 
kenzie Valley;  the  same  may  be  said  of  two  specimens  from  Fort 
McPherson,  which  are  slightly  paler  than  parinjii  and  have  smaller 
skulls. 

Preble  (1908,  p.  162)  has  set  uj)  ^''ItennicottiP  as  a  subspecies  of 
parryii^  considermg  it  to  be  identical  with  C.  p.  'bai^roicensis,  but 
the  recent  acquisition  of  a  lai'ge  series  of  the  latter  form  from  Point 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  95 

Hope,  Alaska,  shows  it  to  be  decidedly  paler  than  typical  'parryii  and 
paler  even  than  the  specimens  representing  "kennicoitii."  In  con- 
sideration also  of  the  occurrence  of  practically  typical  parryii  in 
the  mountains  along  the  Alaska- Yukon  boundary,  lying  to  the  west- 
ward of  the  Mackenzie  Valley,  it  seems  probable  that  when  a  larger 
series  from  the  type  region  of  '■^kennicottii'^  is  made  available,  they 
will  be  shown  to  be  referable  to  parryii. 

The  almost  complete  absence  of  specimens  in  summer  pelage  from 
the  Arctic  coast  of  Mackenzie  and  Alaska  makes  it  difficult  to  deter- 
mine with  certainty  the  western  limits  of  the  present  form  on  that 
coast.  However,  since  the  series  in  summer  pelage  from  Firth  River, 
Yukon,  some  45  miles  back  from  the  coast,  is  clearly  referable  to 
parryii,  it  seems  reasonable  to  consider  that  the  specimens  in  winter 
pelage  from  the  northeast  coast  of  Alaska,  as  far  west  as  CoUinson 
Point,  are  of  the  same  race.  No  specimens  are  available  between 
Collinson  Point  and  Point  Barrow. 

/Specimens  examined. — Total  number,  205,  as  follows : 

Alaska:  Collinson  Point,  11;"^  Hula  Hula  River,  8;"^°^  International  Boundary, 
80  miles  north  of  Porcupine  River,  1 ;  Okpilak  River  (west  of  Barter 
Island),  4;^  Porcupine  River  (12  miles  below  Coleen  River  and  near  Salmon 
Trout  River),  4;  Sadlerochit  River,  2."^ 

Northwest  Territories  [Mackenzie]:  Anderson  River,  2;  Artillery  Lake,  16  (3 
skins  with  skulls,  13  skulls  only)  ;"  Aylmer  Lake,  9*^  (skulls)  ;  Bernard 
Harbor  (Dolphin  and  Union  Strait),  25;*'  Clinton  Golden  Lake,  10;  Cop- 
permine River  (mouth),  3;"'  Cape  Eskimo,  3;^  Cape  Fullerton,  9;*"  Coro- 
nation Gulf,  6 ;  ^'^  **  Deas  Thompson  Point,  1 ;  *'  Dease  Bay,  Great  Bear 
Lake,  2;"  Fort  Anderson,  7  (1  skin,  6  skulls  only)  ;  Fort  Good  Hope,  2; 
Fort  McPherson,  2;  Hanbury  and  Thelon  Rivers  (junction),  5;"  Hudson 
Bay  (25  miles  south  of  Cape  Eskimo),  4;  Kasha  Lake,  2;  Langton  Bay 
(arm  of  Franklin  Bay),  S;*^  Lockhart  River,  2;  "Mackenzie"  (no  labels), 
7 ; ''  Mackenzie  River  Delta,  3 ;  ^'  Marble  Island,  1 ;  Old  Fort  Good  Hope,  4. 

Yukon:  Firth  River  (on  141st.  meridian),  15:  Joe  River  (Firth  River),  17; 
Old  Crow  River  (mouth,  and  50  miles  above  Timber  Creek),  11;  Rampart 
House,  2;  U  Creek  (90  miles  north  of  Rampart  House),  2. 

CITELLUS  PARRYII  BARROWENSIS   (Meemam) 

Babeow  Ground  Sqtjibbel 

Bpermophilus  harrowcnsis  Merriam,  Wash.  Acad.  Sci.  Proc.  2 :  19,  Mar.  14,  1900. 
Spermophilus  beringensis  Merriam,  Wash.  Acad.  Sci.  Proc.  2:  20,  1900   (Cape 
Lisburne,  Alaska). 

Type. — Collected  at  Point  Barrow,  Alaska,  May  30,  1883,  by  Lt. 
P.  H.  Ray ;  male  adult,  skin  and  skull ;  no.  if§4i,  U.  S.  Natl.  Mus. 
(orig.  no.  1428). 

Range. — Arctic  coast  of  Alaska  from  Point  Hope  eastward  at  least 
to  Point  Barrow;  limits  of  range  not  known  (fig.  8).  Zonal  range: 
Arctic. 

External  characters. — Similar  to  C.  p.  parryii,  but  coloration  paler, 
both  above  and  below;  top  and  sides  of  head,  sides  of  neck,  and 
thighs  paler  (less  reddish) ;  similar  in  color  to  C.  p.  ablusus,  but 
upper  parts  averaging  paler  (less  brownish)  ;  sides  of  body  more 
tawny  (less  grayish),  and  under  parts  slightly  darker. 

•"Natl.  Mu.s.  Canada. 

•^Amer.  Mus.  Nat.  Hist. 

"*  Twelve  in  Amer.  Mus.  Nat.  Hist. 


95  NORTH  AMERICAN  FAUNA  [No.  56 

Cranial  characters. — Skull  essentially  like  that  of  parryii. 

Color. — Summer  pelage  (August) :  Top  of  head  (nose  to  occiput) 
tawny  or  russet;  sides  of  face  cinnamon  buff;  sides  of  neck  ochra- 
ceous  tawny ;  upper  parts  sayal  brown  or  mikado  brown,  abundantly 
and  coarsely  flecked  with  whitish  or  warm  buff  spots ;  nape  and  fore- 
back  washed  with  grayish  white ;  legs  cinnamon  ,*■  feet  cinnamon  buff ; 
tail  tawny  or  mikado  brown,  more  or  less  mixed  above  with  black,  tip 
wholly  black;  under  parts  cinnamon  or  cinnamon  buff.  Winter 
pelage  (October-May)  :  Coloration  of  upper  parts  and  sides  more 
grayish  than  in  summer ;  sides  of  nose  pinkish  buff ;  feet  paler  than 
in  summer,  sometimes  pinkish  buff;  under  parts  cinnamon  buff  or 
pinkish  buff. 

Molt. — The  spring  molt  is  not  shown  by  any  of  the  specimens  ex- 
amined, but  probably  it  occurs  in  June,  as  in  the  other  races. 

Measurements. — Average  of  11  adult  males  from  Point  Hope,  Alaska :  Total 
length,  411.6  (383-440)  ;  tail  vertebrae,  118.6  (107-142)  ;  liind  foot,  65  (61-68)  ; 
ear  from  notch  (dry),  7.6  (6-9).  Average  of  10  adult  females  from  Point 
Hope:  Total  length,  390.2  (368-^20);  tail  vertebrae,  113.2  (101-127);  hind 
foot,  61  (59^65)  ;  ear  from  notch  (dry),  6.7  (6^7).  Skull:  Average  of  12  adult 
males  (Point  Barrow,  7;  Point  Hope,  5):  Greatest  length.  60.9  (58-62.9); 
palatilar  length.  32  (30.8-33)  ;  zygomatic  breadth,  40.4  (38.1-42.2)  ;  cranial 
breadth,  24.4  (24.2-25.1)  ;  iuterorbital  breadth,  13  (12.1-13.5)  ;  postorbital  con- 
striction, 13.9  (13-15.5)  ;  length  of  nasals,  23  (21.3-25.4)  ;  maxillary  tooth  row, 
33.9  (13.2-15).  Average  of  6  adult  females  (Point  Barrow,  2;  Point  Hope,  4)  : 
Greatest  length,  59.1  (57.8-60.8)  ;  palatilar  length,  30.9  (30-31.8)  ;  zygomatic 
breadth,  39.7  (37.9-41.2)  ;  cranial  breadth,  23.2  (22.4-24.1)  ;  Interorbital 
breadth,  12.9  (12.2-14.6)  ;  postorbital  constriction,  12.7  (12-14.4)  ;  length  of 
nasals,  21.9  (20.9^23.1)  ;  maxillary  tooth  row,  13.4   (13-13.9). 

Remarks. — The  ground  squirrels  inhabiting  the  northwest  coast  of 
Alaska  are  distinctly  paler  than  typical  parryii  from  Hudson  Bay. 
The  series  of  eight  summer  skins  from  Point  Barrow  agrees  essen- 
tially with  a  large  series  from  Point  Hope,  recently  collected  by 
R.  M.  Gilmore  for  the  Museum  of  Vertebrate  Zoology;  hence  the 
name  C.  p.  heHngensis.^  based  originally  on  two  skins  without  skulls 
from  Cape  Lisburne,  is  placed  in  the  synonymy  of  C.  p.  harrotoensis., 
the  latter  name  having  page  priority.  The  subspecies  ranges  east- 
ward on  the  coast  at  least  to  Point  Barrow  and  possibly  farther,  but 
no  specimens  have  been  seen  from  points  between  Point  Barrow  and 
Collinson  Point.  The  majority  of  the  specimens  available  from  the 
Arctic  coast  of  northeastern  Alaska  and  Mackenzie  are  in  winter 
pelage,  in  which  pelage  the  characters  are  less  pronounced;  a  good 
series  in  summer  pelage  is  needed  to  determine  with  certainty  the 
limits  of  range  of  the  two  races,  parryii  and  harroioensis. 

Specimens  examined.- — Total  number,  69,  as  follows: 

Alaska:  Cape  Lisburne,  4  (2  skins,  2  separate  skulls)  ;  Cape  Thompson,  1  ;^' 
Point  Barrow,  31  (15  skins;  16  extra  skulls)  ;  Point  Hope,  30";  Wain- 
wright,  2  " ;  Wainwright  Inlet,  1. 

«=  Mus.  Vert.  Zool. 

««  Twenty-eight  in  Mus.  Vert.  Zool. 

«^  Colorado  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  97 

CITELLUS  PARRYII  PLESIUS   (Osgood) 

Yukon  Ground  Sqtjibbel 

(Pis.  24,  D;  29,  D) 

Spermophiltis  empetra  plesius  Osgood,  North  Amer.  Fauna  19:  29,  Oct.  6,  1900. 
Ciitellusl  plesius  Osgood,  Biol.  Soc.  Wash.  Proc.  16:  25,  1903. 
Citellus  erythrogluteius  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  19:  534,  1903  (not 
Arctomys  parryi  var.  j8  erythrogluteia  Richardson). 

Type. — Collected  at  Bennett  City,  head  of  Lake  Bennett,  British 
Columbia,  June  19,  1899,  by  W.  H.  Osgood;  female  adult,  skin  and 
skull,  no.  98931,  U.  S.  Natl.  Mus.  (Biological  Survey  collection) 
(orig.  no.  465), 

Rmige. — Northwestern  British  Columbia,  greater  part  of  Yukon 
(except  extreme  northern  part)  and  mountainous  parts  of  Mackenzie 
(west  of  the  Mackenzie  River) ;  north  to  the  Ogilvie  Range  (head 
of  Coal  Creek),  Yukon;  east  to  Fort  Liard  and  the  Nahanni  Hills, 
Mackenzie;  south  to  vicinity  of  Tatletuey  Lake,  British  Cohunbia; 
west  to  Glacier,  British  Columbia,  and  Delta  River  (Ober  Creek), 
Alaska  (fig.  8).    Zonal  range:  Hudsonian. 

External  characters. — Similar  to  G.  p.  'parryii^  but  decidedly 
smaller;  coloration  much  paler  and  more  grayish  (less  tawny)  above; 
sides,  under  parts,  and  feet  paler ;  dorsal  spots  smaller. 

Cranial  characters. — Skull  similar  to  that  of  parryii^  but  much 
smaller;  rostrum  and  nasals  shorter;  zygomata  less  widely  expanded; 
frontal  shield  less  elevated;  temporal  ridges  less  distinctly  lyrate  than 
in  C.  p.  lyratus  and  C.  kodiacensis,  but  not  united  posteriorly  in  a 
prominent  crest  as  in  C  p.  ahlusus.  Teeth  similar;  posterior  loph  on 
m^  usually  continuous  and  well  developed. 

Color. — Summer  pelage:  Head  and  front  of  face  tawny  or  sayal 
brown ;  sides  of  nose  clay  color  or  cinnamon  buff ;  sides  of  head  and 
neck  ochraceous  tawny  or  cinnamon  buff,  mixed  with  fuscous;  gen- 
eral tone  of  upper  parts  buffy  gray,  caused  by  a  mixture  of  fuscous, 
pinkish  buff,  and  grayish  white  (the  hairs  being  fuscous  subter- 
minally  and  tipped  with  whitish  or  pinkish  buff) ;  back  moderately 
sprinkled  with  grayish  white,  squarish  spots  (sometimes  indistinct 
or  nearly  obsolete) ;  sides  and  under  parts  ochraceous  tawny  or  cin- 
namon buff;  feet  cinnamon,  cinnamon  buff,  or  clay  color;  tail  above 
mixed  cinnamon  and  fuscous,  becoming  fuscous  black  on  distal  half, 
and  edged  with  pinkish  buff;  tail  beneath,  tawny  or  pale  russet,  the 
tip  fuscous  black.  Winter  pelage  (Sept.  19) :  Upper  parts  and  sides 
pale  smoke  gray  shaded  with  fuscous  and  washed  in  middle  of  back 
with  cinnamon  buff;  under  parts  grayish  white,  thinly  washed  with 
pinkish  buff;  otherwise  as  in  summer. 

Molt. — The  spring  molt  takes  place  in  late  June;  two  specimens 
from  Bennett,  British  Columbia,  June  18  and  22,  are  in  badly  worn 
winter  pelage,  with  new  pelage  covering  the  head,  nape,  and  most 
of  the  under  parts.  Specimens  showing  the  fall  molt  are  not  avail- 
able, but  one  from  Bennett  taken  September  19  is  apparently  in  full 
winter  pelage. 

Measurements. — Average  of  10  adult  males  from  type  locality :  Total  length, 
339.2  (320-363)  ;  tail  vertebrae,  95.5  (85-105)  ;  hind  foot,  54  (50-57).  Average 
of  8  adult  females  from  Bennett,  British  Columbia,  and  head  of  Coal  Creek, 
Yukon:  Total  length,  329  (300-352)  ;  tail  vertebrae,  90.4  (85-102)  ;  hind  foot, 
52.9  (52-54).     SlcuU:  Average  of  10  adult  males  from  type  locality:  Greatest 

154970—38 7 


gg       '  NORTH  AMERICAN  FAUNA  [No.  56 

length,  53.5  (51.5-56.4)  ;  palatilar  length,  26.2  (25-28)  ;  zygomatic  breadth, 
34.6  (33.5-35.5)  ;  cranial  breadth,  22.5  (21.4-23.3)  ;  interorbital  breadth,  11.2 
(10.2-12.2)  ;  postorbital  constriction,  13.2  (12.6-13.7)  ;  length  of  nasals,  19 
(17.7-20.7)  ;  maxillary  tooth  row,  12  (11.4-12.4).  Average  of  10  adult  females 
from  type  locality:  Greatest  length,  52  (50.7-53.3)  ;  palatilar  length,  25.5  (25- 
26)  ;  zygomatic  breadth,  33.5  (32.2-^4.9)  ;  cranial  breadth,  21.6  (21.1-22.1)  ; 
interorbital  breadth,  10.5  (10-11.4)  ;  postorbital  constriction,  12.6  (11.9^13.1)  ; 
length  of  nasals,  18.7   (18.1-19.8)  ;  maxillary  tooth  row,  li;7   (11.1-12.3). 

Weight. — An  adult  female  (Chitina  River,  Alaska)  weighed  slightly  over  one 
pound   (no  embryos). 

Remarks. — The  Yukon  ground  squirrel  is  distinguishable  from 
parryii  and  G.  osgoodi  by  its  smaller  size  and  paler  coloration.  It 
occupies  the  greater  part  of  the  Province  of  Yukon  (except  the  por- 
tion north  of  the  Porcupine  River)  as  well  as  parts  of  Mackenzie 
and  British  Columbia,  and  ranges  westward  into  Alaska,  where  it 
merges  into  the  subspecies  dblusus.  Southward  it  does  not  reach  the 
range  of  G.  columbianus. 

Specimens  from  the  headwaters  of  Telegraph  Creek  and  Sheslay 
River,  northern  British  Columbia,  were  assigned  by  J.  A.  Allen 
(1903a,  p.  534)  to  Gitellus  erythrogluteius  (Richardson)  on  the  as- 
sumption that  its  type  locality — "head  of  Elk  River,  Rocky  Momi- 
tains" — is  in  latitude  57°,  as  indicated  by  Richardson.  As  shown, 
however,  on  page  88,  the  Elk  River  of  Richardson  is  the  Athabaska, 
whereas  the  type  locality  of  erythrogluteia  is  actually  near  the  head- 
waters of  Sulphur  River,  Alberta. 

Specimens  examined. — Total  number,  158,  as  follows : 

Alaska:  Chitina  River  Glacier,  4;**  Ober  Creek  (Jarvis  Creek,  Delta  River 
region),  2;  Tanana  Crossing,  1;  Tanana  Hills,  2;  White  Pass,  5. 

British  Columbia:  Bennett,  38;  Chapa-atan  River  (Stikine  River,  near  head),  8; 
Cassiar  Mountains  (near  Dease  Lake),  2;  Ispatseezeh  River  (Stikine  River, 
near  head),  3;  Klappan  River  Valley  (near  head),  1;  Little  Klappan  River 
(headwaters),  1;  McDame  Creek  (Dease  River),  3;  McKee  Creek,  Atlin 
District,  1;°*  Rapid  River  (Dease  River),  1;  Sheep  Mountain  (Dease 
River),  2;  Sheslay  River  (timber  line,  4,000  feet  altitude),  1;  Tatletuey 
Lake,  1;  Telegraph  Creek  (near  head),  6;  Wilson  Creek,  Atlin  District,  5.*" 

Northwest  Territories  [Mackenzie] :  Fort  Liard,  1 ;™  Fort  Norman  (mountains 
west),  1;  Fort  Simpson  [probably  from  Nahanni  Hills],  1;"  Mackenzie 
Mountains,  2." 

Yukon:  Coal  Creek  (near  head),  18;  Donjek  River,  2;  Livingston,  1;"  Pelly 
Lake,  1;  Pelly  River  (Lapie  River),  6;  Tantalus,  1;**  Teslin  Lake  (and 
vicinity),  25;°'  Yukon  River,  17  (Caribou  Crossing,  6;  Fifty-mile  River,  1; 
Lake  Lebarge,  2;  Lake  Marsh,  6;  Miles  Canyon,  1 ;  Rink  Rapids,  1). 

CITELLUS   PARRYII  ABLUSUS   Osgood 

Aleutian  Geound  Squirrel 

Gitellus  plesius  ablusus  Osgood,  Biol.  Soc.  Wash.  Proc.  16:  25,  Mar.  19,  1903. 
Gitellus  stonei  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  19 :  537,  1903  ( Stevana  Flats, 

near  Port  Moller,  Alaska  Peninsula  (not  Wraugell),  Alaska).     (Allen,  op. 

cit.  p.  XVII). 

Type. — Collected  at  Nushagak,  Alaska,  September  16,  1902,  by 
W.  H.  Osgood  and  A.  G.  Maddren;  male  adult,  skin  and  skull,  no. 
119815,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig. 
no.  2043). 


«8Natl.  Mus.  Canada. 

**  Provincial  Mus.,  Victoria,  B.  C. 

''"Univ.  of  Michigan  Mus.  Zool. 

■^  Field  Mus.  Nat.  Hist. 

^2  Amer.  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  QQ 

Range.— Alaska,  mainly  south  of  the  Yukon  Valley ;  north  on  the 
coast  to  Eschscholtz  Bay;  west  on  the  Alaska  Peninsula  to  its  tip; 
south  to  base  of  the  Kenai  Peninsula ;  east  to  headwaters  of  Tanana 
River;  introduced  on  Unalaska,  Uninak,  and  Kavalga  Islands  (fig.  8). 
Zonal  range:  Hudsonian  and  Arctic. 

External  characters. — Similar  in  color  to  0.  p.  plesius  but  upper 
parts  (in  summer)  more  brownish  (less  grayish) ;  dorsal  spotting 
less  distinct  and  spots  smaller;  under  parts  averaging  paler;  tail 
usually  more  blackish,  the  under  surface  a  slightly  darker  shade  of 
russet;  skull  larger  and  relatively  narrower.  Compared  with  C.  p. 
parry ii:  Size  much  smaller;  dorsal  spots  smaller;  coloration  paler, 
especially  on  the  under  parts,  sides  of  neck  legs,  and  mider  surface  of 
tail.  Compared  with  G.  p.  harrowensis :  Size  smaller;  coloration  of 
upper  parts  darker  (more  brownish) ;  sides  paler  (less  tawny) ;  under 
parts  averaging  j)aler. 

Cranial  characters. — Skull  larger  than  that  of  plesius,  with  rela- 
tively narrower  brain  case ;  rostrum  and  nasals  longer ;  audital  bullae 
larger — both  longer  and  broader — but  rather  flat;  temporal  ridges 
less  distinctly  lyrate  in  shape  than  in  G.  p.  lyratus  and  G.  kodi- 
accTisis,  uniting  posteriorly  to  form  a  slight  crest;  skull  decidedly 
smaller  than  that  of  haj-^rowensh  or  pai^yii. 

Golor. — Summer  pelage:  Top  of  head  and  face  russet  or  tawny; 
sides  of  head  pinkish  buff  or  cinnamon  buff,  shaded  with  fuscous; 
front  legs  and  sides  of  neck  tawny;  upper  parts  walnut  brown, 
washed  on  neck  and  shoulders  with  pale  buff,  and  abundantly  flecked 
with  irregular,  buffy  white  spots ;  fore  and  hind  feet  clay  color ;  tail 
above,  mixed  cinnamon  buff  and  fuscous  black,  becoming  solid 
blackish  on  distal  fourth ;  tail  beneath,  russet  or  tawny ;  under  parts 
clay  color  or  cinnamon  buff.  Worn  lointer  pelage:  General  tone  of 
upper  parts  snuff  brown,  washed  on  neck  and  shoulders  with  pale 
smoke  gray;  sides  of  head  and  neck  smoke  gray;  sides  of  body  pale 
buff  mixed  with  white;  under  parts  gi-ayish  white,  faintly  washed 
with  pinkish  buff;  otherwise  as  in  summer. 

Molt. — The  beginning  of  the  spring  molt  is  shown  by  an  adult  male 
specimen  taken  June  16  at  Lake  Aleknagik,  Alaska ;  new  hair  is  ap- 
pearing on  the  head,  shoulders,  and  fore  legs,  the  rest  of  the  body 
being  in  worn  winter  pelage. 

Measurements. — Average  of  8  adult  males  from  Nushagak  and  Swau  Lake, 
Alaska:  Total  length,  874.5  (SHD^SIM)  ;  tail  vertebrae,  102.8  (05-108);  hind 
foot,  58.5  (55-61).  Average  of  6  adult  females  from  same  localities:  Total 
length,  346.3  (340-356)  ;  tail  vertebrae,  99.5  (95-108)  ;  hind  foot,  56.2  (55-59). 
Skull:  Average  of  7  adult  males  from  Nushagak,  Alaska:  Greatest  length,  57 
(55.7-58.8)  ;  palatilar  length,  28.4  (27-29.5)  ;  zygomatic  breadth,  36.7  (35.4^ 
38.5)  ;  cranial  breadth,  23  (22.6-23.7)  ;  iuterorbital  breadth,  12.G  (11.6-14)  ; 
postorbital  constriction,  13.3  (12.3-14)  ;  length  of  nasals,  21.1  (19.8-22.6)  ; 
maxillary  tooth  row,  12.3  (11.8-12.9).  Average  of  7  adult  females  from  Nush- 
agak: Greatest  length,  55.3  (54.2-57.1);  palatilar  length,  27.7  (27-29);  zygo- 
matic breadth,  35  (33.8-36.4)  ;  cranial  breadth,  22.2  (21.5-22.5)  ;  iuterorbital 
breadth,  12.1  (11-5-13)  ;  postorbital  constriction,  13  (12-14)  ;  length  of  nasals, 
12  (11.4-12.4). 

Remarks. — The  Aleutian  ground  squirrel  is  closely  related  to 
plesius,  with  which  it  intergrades  in  eastern  Alaska.  Material  is 
lacking  to  show  the  exact  limits  of  its  range  eastward.  Certain 
specimens  from  Nome,  on  the  Seward  Peninsulaj  show  approach  to 
harrowensis  in  their  larger  skulls;  intergradation  with  that  race 
doubtless  occurs  between  Eschscholtz  Bay  and  Point  Hope. 


IQQ  NORTH  AMERICAN  FAUNA  [No.  56 

Comparison  of  the  type  of  C.  ^^stonei'^  and  a  good  series  from  the 
type  region  with  typical  ablusus  shows  no  characters  to  separate  the 
two  forms.  Hence  '■^stoneP  (supposed  at  the  time  it  was  described 
to  have  come  from  Wrangell,  Alaska)  falls  in  the  synonymy  of  C.  p. 
ablusus,  Avhich  has  several  months'  priority. 

In  the  summer  of  1913,  18  ground  squirrels  of  this  subspecies  were 
captured  at  Nushagak  and  shipped  to  St.  George  Island  in  a  single 
large  crate. 

Although  plentifully  supplied  with  green  food,  they  preyed  on  each  other,  and 
while  this  tendency  was  overcome  to  some  extent  by  supplying  them  with  meat, 
the  stock  of  18  had  been  reduced  to  5  before  they  reached  their  destination. 
These  five,  an  adult  and  four  young,  including  both  sexes,  were  liberated  on  St. 
George ;  at  least  two  survived  until  May  1914,  but  by  the  summer  of  that  year 
all  apparently  had  disappeared  (Osgood,  Preble,  and  Parker,  1915,  p.  129). 

This  subspecies  is  closely  similar  to  C.  huxtoni  (Allen,  1903c,  p. 
139)  of  eastern  Siberia,  differing  chiefly  in  less  intensely  tawny 
coloration,  and  more  blackish  tail ;  in  these  characters  huxtoni  closely 
resembles  G.  p.  parryii,  which,  however,  is  decidedly  larger;  since 
huxtoni  intergrades  in  characters  with  ablusus,  it  may  well  be  given 
subspecific  status  under  the  name  Citellus  parryii  huxtoni. 

Specimens  examined. — Total  number,  274,  as  follows: 

Alaska:  Alaska  Peninsula,  110  (Chignik,  24;  Cold  Bay,  10;  Frosty  Peak,  17; 
Herendeen  Bay,  7 ;  "  Izembek  Bay,  1 ;  Katmai,  2 ;  Kings  Cove,  5 ;  Kukak 
Bay,  5 ;  Moller  Bay,  S ; "  Morzhovoi  Bay,  8 ;  Pavlof  Mountain,  2 ;  Portage 
Bay,  20;  Stepovak  Bay,  1)  ;  Anchorage,  1; "  Bristol  Bay,  1;  Cape  Prince  of 
Wales,  4 ;  Eschscholtz  Bay,  4 ;  Golofnin  Bay,  1 ;  Jennie  Creek,  Mount  Mc- 
Kinley  Park,  1 ;  Kakhtul  River,  4 ;  Kanulik,  3 ;  Kavalga  Island,  2 ;  Kokwok 
River,  1;  Lake  Aleknagik,  20;  Lake  Clark,  4;  Mount  McKinley,  19;  Nome, 
Y .  74  75  Nusiiagak,  14 ;  Savage  River,  Mount  McKinley  Park,  3 ;  Pavlof  Moun- 
tain, 1;  "  Swan  Lake  (Mulchatna-Chulitua  Portage),  4;  Teller,  1; ''  Togiak, 
1 ;  Unalaska  Island,  55 ;  Unimak  Island,  11 ;  Ushagat  Island,  2. 

CITELLUS  PARRYII  NEBULICOLA  Osgood 
Shumagin   Geound   Squieeel 

Citellus  neluUcola  Osgood,  Biol.  Soc.  Wash.  Proc.  16:  26,  Mar.  19,  1903. 

Type. — Collected  on  Nagai  Island,  Shumagin  Islands,  Alaska, 
June  24,  1893,  by  C.  H.  Townsend ;  female  adult,  skin  and  skull,  no. 
69145,  U.  S.  Natl.  Mus.  _ 

Range. — The  Shumagin  Islands  (Nagai,  Simeonoff,  and  Koniuji), 
Alaska  (fig.  8).    Zonal  range:  Hudsonian. 

External  characters. — Very  similar  in  color  to  G.  p.  ablusus,  but 
smaller,  with  shorter  tail  and  hind  feet.  Compared  with  G.  kodia- 
censis:  Size  smaller;  coloration  of  upper  parts  more  brownish  or 
ochraceous  (less  grayish)  ;  under  parts  darker;  tail  in  summer  pel- 
age more  tawny  (less  blackish). 

Granial  characters. — Skull  similar  to  that  of  kodiacensis  and 
ablusus  but  averaging  smaller,  with  relatively  longer  tooth  row; 
closely  similar  to  that  of  G.  p.  plesius,  but  nasals  slightly  longer, 
narrower  at  posterior  end.  and  elevated  along  the  median  suture.  In 
two  of  the  skulls  examined  the  posterior  loph  on  7n  ^  is  discontinuous, 
in  this  character  shov/ing  approach  to  kodiacensis. 


'^Amer.  Mua.  Nat.  Hist. 
"•^  Mus.  Comp.  Zool. 
■^  Colorado  Mus.  Nat.  Hist. 
''^  Carnegie  Mus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  IQl 

Color. — SmiiTner  pelage:  Top  of  head  and  face  russet  or  tawny; 
eye  ring  pinkish  buff  or  buffy  white;  sides  of  nose  pinkish  buff, 
sides  of  face  cinnamon  buff,  shaded  with  fuscous;  sides  of  neck, 
and  front  legs,  ochraceous  tawny;  upper  parts  snuff  browtn  or 
verona  brown,  sprinkled  with  cinnamon  and  abundantly  flecked 
with  creamy  white  spots;  feet  cinnamon  buff  or  clay  color,  the  toes 
pinkish  buff;  tail  above,  fuscous  black,  mixed  with  cinnamon  or 
cinnamon  buff  and  edged  with  pinkish  buff;  tail  beneath,  russet  or 
mikado  brown,  tipped  with  fuscous  black;  under  parts  clay  color, 
shading  to  pinkish  buff  on  tliroat.  Winter  pelage:  Upper  parts 
similar  to  the  summer  pelage  but  much  more  whitish,  the  snuff  brown 
hairs  more  extensively  tipped  with  white,  and  the  shoulders  and  sides 
pale  smoke  gray ;  tail  above,  fuscous  black,  faintly  shaded  with  sayal 
brown  and  edged  with  buffy  white ;  tail  beneath,  snuff  brown  or  cin- 
namon brown,  tipped  with  black;  feet  pale  pinkish  buff;  under  parts 
white,  faintly  shaded  with  pale  pinkish  buff. 

'  Molt. — A  specimen  taken  May  16  is  in  worn  winter  pelage,  showing 
new  summer  fur  appearing  in  scattered  patches  on  the  head  and 
back. 

Measurements. — Average  of  3  adult  males  (measured  dry)  :  Tail  vertebrae, 
79.7  (77-S2)  ;  in  8  adults  (4  males,  4  females)  the  hiud  foot  (dry)  averages 
r)2.1  (50-55.7).  Skull:  Average  of  4  adult  females:  Greate.'^t  length,  52.6  (50.7- 
55.4)  ;  palatilar  length,  20.2  (25.5-27)  ;  zygomatic  breadth,  33.7  (32-35)  ;  cranial 
breadth,  21.7  (21.1-22.2)  ;  interorbital  breadth,  11.4  (11.1-11.8)  ;  postorbital 
constriction,  12  (11-13.2)  ;  length  of  nasals,  19.4  (18.2-20)  ;  maxillary  tooth  row, 
11.5    (11.3-11.7). 

Remarks. — This  depauperate  insular  race  shows  relationship  both 
to  ablusus  of  the  mainland  and  to  kodiacensls  of  Kodiak  Island. 
The  material  at  hand  is  too  limited  to  show  clearly  its  exact  rela- 
tionship to  the  other  forms  of  the  species,  but  since  its  characters 
overlap  those  of  ahlusus  it  is  assigned  a  subspecific  relationship 
with  that  race. 

Specimens  examined. — Total  number,  15,  as  follows: 

Alaska:  Shumagin  Islands,  15  (Nagai  Island,  10;  Koniu.ii  Island,  1;  Simeonof 
Island,  4). 

CITELLUS  PARRYII  LYRATUS  ILu.l  and  Gilmorb 

St.  Lawkence  Island  Gkound  Squikrel 

(Pis.  24,  B;  29,  B) 

Citellus  lyratus  Hall  and  Gilmore,  Calif.  Univ.  Pubs.,  Zool.  38:  396,  Sept.  17,  1932. 

Type. — Collected  at  Iviktook  Lagoon  (about  35  miles  northwest 
of  Northea.st  Cape),^^  St,  Lawrence  Island,  Beriag  Sea,  Alaska,  July 
7,  1931,  by  Raymond  M.  Gilmore;  male  adult,  skin  and  skull,  no. 
51172,  Mus.  Vert.  Zool.  (orig.  no.  1738). 

Range. — St.  Lawrence  Island,  Bering  Sea,  Alaska  (fig.  8). 
Zonal  range:  Arctic. 

External  characters. — Similar  to  C.  p.  ahlusus,  of  the  Alaska 
Peninsula,  but  upper  parts  paler  and  more  grayish  (less  brownish)  ; 
under  parts,  sides  of  nock,  legs,  and  feet  paler  buff;  tail  longer  and 
more  grayish    (less  tawny)    above   and  paler  beneath.     Compared 

"  Location  as  defined  by  R.  M.  Gilmore,  August  1933. 


102  NORTH  AMERiaVN  FAUNA  [No.  56 

with  C.  p.  nebulicola:  Size  larger;  colors  paler  throughout;  tail 
above  mainly  blackish  or  grayish  rather  than  tawny. 

Cranial  characters. — Skull  similar  in  size  and  proportions  to  that 
of  dblusus,  differing  from  it  in  the  absence  of  a  prominent  sagittal 
crest,  the  temporal  ridges  being  lyrate  in  shape,  meeting  at  the 
posterior  end  only  in  old  age  to  form  a  very  slight  crest ;  nasals  rela- 
tively broader  at  posterior  end ;  posterior  loph  on  m  ^  well  developed 
and  continuous  (as  in  G.  huxtoni  and  ablusus). 

Color. — Summer  pelage  (July)  :  Top  of  head  mikado  brown;  sides 
of  face  pinkish  buff;  front  legs  and  sides  of  neck  cinnamon  buff; 
general  tone  of  upper  parts  light  brown,  heavily  spotted  with  white, 
the  individual  hairs  plumbeous  at  base,  then  light  pinkish  buff,  then 
pale  fuscous,  and  tipped  with  white ;  thighs  cinnamon  buff ;  hind  feet 
pinkish  buff;  under  parts  cinnamon  buff,  the  throat  clay  color;  tail 
above  (much  worn),  grayish  white,  shaded  with  dull  buffy,  the  tip 
fuscous  or  fuscous  black;  tail  beneath,  dull,  pale  russet,  edged  with 
grayish  white  and  tipped  with  fuscous  black.  Worn  pointer  pelage 
(June  23  and  25)  :  Upper  parts  chiefly  drab  or  wood  brown;  sides 
grayish  white;  feet  pale  pinkish  buff";  under  parts  white  or  dull 
cinnamon  buff. 

Molt. — The  molt  apparently  takes  place  in  June  or  early  in  July; 
specimens  taken  June  23  and  25  are  in  badly  worn  winter  pelage, 
with  new  hair  showing  in  patches  on  the  head,  back,  and  under 
parts. 

Measurements. — Average  of  4  adults  (3  males,  1  female)  from  type  locality: 
Total  length,  370  (350-381)  ;  tail  vertebrae,  107  (97-114)  ;  hind  foot,  57.2  (54- 
60).  Skull:  Average  of  7  adult  males:  Greatest  length,  57.4  (56.2^58.7); 
palatilar  length,  28.7  (28-29.5)  ;  zygomatic  breadth,  36.6  (35.8-37.3)  ;  cranial 
breadth,  22.9  (22.2-23.3)  ;  interorbital  breadth,  12.8  (12.1-13.9)  ;  postorbital  con- 
striction, 13.8  (13.2-14.1)  ;  length  of  nasals,  21.2  (20.5-21.7)  ;  maxillary  tooth 
row,  12  (11.8-12.4).  Average  of  4  adult  females:  Greatest  length.  54.3  (53- 
56.6)  ;  palatilar  length,  27.4  (27-28)  ;  zygomatic  breadth,  34.2  (33.4-34.9)  ; 
cranial  breadth,  22  (21.5-22.6)  ;  interorbital  breadth,  11.8  (11.6-12.2)  ;  post- 
orbital  constriction,  13.4  (13-13.9)  ;  length  of  nasals,  19.8  (19.2-20.4)  ;  maxillary 
tooth  row,  11.9  (11.5-12.3). 

RcTYiarks. — The  St.  Lawrence  Island  ground  squirrel  seems  to  be 
most  nearly  related  to  the  form  occurring  at  Emma  Harbor,  Siberia,^^ 
which  in  turn  is  very  close  to  allusus  of  the  Alaska  Peninsula,  but 
differs  from  it  in  slightly  paler  coloration  and  in  having  a  longer  tail. 
In  skull  characters,  also,  lyratus  agrees  with  the  Asiatic  species  in  the 
lyrate  shape  of  the  temporal  ridges  and  in  tooth  characters.  C.  huoe- 
toni,  from  Gichiga,  Siberia,  is  decidedly  richer  (more  tawny)  in 
color  than  either  lyratus  or  ahlusus,  and  has  the  upper  surface  of 
the  tail  more  ochraceous,  less  suffused  with  black. 

The  present  form  is  much  more  grayish  (less  tawny)  than  either 
ahlicsus  or  huxtoni.  It  is  decidedly  smaller,  as  well  as  paler  colored, 
than  paiTyii  of  the  Arctic  coast  of  Alaska.  It  differs  from  C. 
kodiacensis  in  paler  colors  of  the  dorsal  surface,  feet,  and  tail, 
coarser  spotting,  and  in  the  crown  pattern  of  the  last  upper  molar. 

Specimens  examined. — Total  number,  41,^°  from  St.  Lawrence 
Island. 


Tsrptjg  ground  squirrels  of  the  Chukchi  Peninsula  (Emma  Harbor,  Plover  Bay,  and 
Koliuchin  Bay)  may  prove  to  be  referable  to  C.  stejnegeri  of  Kamchatl^a,  but  the  single 
specimen  (the  type)  of  stejnegeri  now  available  is  too  young  and  too  much  worn  to  permit 
of  satisfactory  comparison. 

■'s  15  in  Mus.  Vert.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  103 

CITELLUS  KODIACENSIS    (Aixen) 
KoDiAK  Ground  Squibbel 

Spermophilus  parryi  var.  kodiacensis  Allen,  Boston  See.  Nat.  Hist.  Proc.  16: 

292,  1874. 
[Spermophilus  empeti-a]  var.  kodiacensis  Allen,  Monog.  North  Amer.  Rodentia, 

p.  839,  1877. 
[Citellus  parryi]  kadiacensis  Trouessart,  Cat.  Mamm.,  Sup.,  p.  338,  1904. 

Lectotype  ^^ — Collected  on  Kodiak  Island,  Alaska,  June  1868,  by 
Ferdinand  Bischoff ;  female  adult,  skin  and  skull,  no.  ^^^j^,  U.  S 
Natl.  Mus. 

Range. — Kodiak  Island  (fig.  8).    Zonal  range:  Hudsonian. 

External  characters. — Similar  to  G.  parryii  ahlusus  but  dorsal  spots 
smaller  and  more  abundant  (though  sometimes  nearly  obsolete) ; 
general  tone  of  upper  parts  in  summer  pelage  more  grayish  (less 
suffused  with  ochraceous). 

Cranial  characters. — Skull  similar  to  that  of  ahliisus  but  molar 
teeth  averaging  slightly  smaller ;  m  ^  with  posterior  loph  poorly  de- 
veloped and  often  not  continuous,  but  broken  by  a  median  sulcus; 
temporal  ridges  lyrate  in  shape  (as  in  G.  p.  lyratus)  not  uniting  pos- 
teriorly in  old  age  to  form  a  prominent  crest. 

Golor. — Summer  felagc.  Head  and  front  of  face  tawny  or  pale 
russet,  (this  color  reaching  back  only  to  front  border  of  ears)  ;  sides 
of  nose  pinkish  buff;  sides  of  face  and  neck  cinnamon  buff  mixed 
with  fuscous,  shading  to  ochraceous  tawny  on  throat  and  base  of  fore 
legs;  upper  parts  from  crown  to  root  of  tail  mixed  fuscous  and 
cinnamon  buff  (the  general  tone  near  snuff  brown) ,  extensively  tipped 
with  buffy  white,  usually  appearing  as  small  irregular  spots;  shoul- 
ders washed  with  cinnamon  buff;  sides  of  body  like  back  but  more 
grayish  (less  brownish) ;  feet  clay  color  or  pinkish  buff;  tail  above 
chiefly  fuscous  black,  mixed  with  tilleul  buff  and  bordered  with  the 
same;  shaded  near  base  with  sayal  brown;  tail  beneath,  sayal  brown 
or  mikado  brown,  much  mixed  with  buff,  the  tip  fuscous  black;  under 
parts  cinnamon  buff  or  pinkish  buff.  ^Y inter  pelage :  (April  and  May 
specimens) :  Similar  to  the  summer  pelage  but  tips  of  hairs  on  upper 
parts  more  whitish,  especially  on  shoulders;  sides  of  head,  neck,  and 
body  mainly  grayish  white,  with  little  buff;  feet  pinkish  buff  or 
buffy  white ;  under  parts  grayish  white,  faintly  washed  with  pinkish 
buff. 

Measurements. — Average  of  10  adult  males  from  Kodiak  Island :  Total  length, 
358.2  (332-400)  ;  tail  vertebrae,  96.5  (81-112)  ;  hind  foot,  56.4  (52-60).  Aver- 
age of  10  adult  females  from  same  locality :  Total  length,  353.2  (333-375)  ;  tail 
vertebrae,  96.4  (77-104)  ;  hind  foot,  54.7  (51-58).  Skull:  Average  of  10  adult 
males  from  Kodiak  Island:  Greatest  length,  56.2  (55-57.8);  palatilar  length, 
28  (27-29)  ;  zygomatic  breadth,  36.8  (35.7-37.6)  ;  cranial  breadth,  23.3  (22.9-24)  ; 
interorbital  breadth,  12.3  (11.8-13.6)  ;  postorbital  constriction,  12.5  (11.4-14.2)  ; 
length  of  nasals,  21  (19.6-21.9)  ;  maxillary  tooth  row,  11.7  (11.2-12.7).  Aver- 
age of  10  adult  females  from  same  locality:  Greatest  length,  54.4  (51.8-55.7)  ; 
palatilar  length,  27.2  (25.5-28)  ;  zygomatic  breadth,  35.5  (34.5-36.8)  ;  cranial 
breadth,  22.6  (21.7-23.2)  ;  interorbital  breadth,  12  (11.5-12.5)  ;  postorbital 
constriction,  12.5  (11.5-13.7)  ;  length  of  nasals,  20.5  (18.5-21.3)  ;  maxillary 
tooth  row,  11.4  (10.3-12). 


*>  No  type  was  designated  :  this  specimen  is  tlie  only  one  of  tiiose  listed  by  Allen  in 
liis  monograpli  (1877,  p.  848),  now  remaining  in  tiie  National  Museum  collection  It  is 
liereby  designated  as  a  lectotype. 


104  NORTH  AMERICAN  FAUNA  [No.  56 

Remarks. — The  Kodiak  ground  squirrel  is  closely  related  to 
ablusus^  inhabiting  the  nearby  mainland,  but  since  it  differs  in  both 
cranial  and  color  characters  it  is  considered  a  distinct  species.  Os- 
good states  (1903,  p.  27),  on  the  authority  of  a  native,  that  the 
spermophiles  on  Kodiak  Island  Trere  introduced  from  North  Semidi 
Island;  no  specimens  from  the  latter  island  have  been  seen,  but  the 
rather  pronounced  characters  of  kodiacensis  indicate  that  the  species 
probably  has  occupied  Kodiak  Island  for  a  long  period. 

Specimens  examined. — Total  number,  45,  from  Kodiak  Island. 

CITELLUS   OSGOODI    (Merbiam) 

Yukon  Vaixkt  Ground  Squtreel 

(Pis.  24,  C;  29,  0) 

Spermophilus  osgoodi  Merriam,  Wash.  Acad.  Sci.  Proc.  2 :  18,  Mar.  14,  1900. 
[Citellus]  osgoodi  Osgood,  Biol.  Soc.  Wash.  Proc.  16:  27,  1903. 

7'2/;?e.— Collected  at  Fort  Yukon,  Alaska.  April  29,  1877,  by  L.  M. 
Turner;  male  adult,  skin  and  skull;  no.  iHM;  U.  S.  Natl.  Mus.  (orig. 
no.  1635). 

Range. — Tlie  Yukon  Valley,  from  a  point  about  25  miles  above 
Circle  to  the  Yukon  Flats,  west  of  Fort  Yukon  and  possibly  to  the 
mouth  of  the  Tanana  (Osgood,  1900,  p.  31)  (fig.  8).  Zonal  range: 
Hudsonian. 

External  characters. — Similar  to  C.  pann/ii  parry ii  but  tail  longer; 
coloration  darker  (more  reddish)  and  dorsal  spots  smaller;  feet 
darker. 

Cranial  charaxiters. — Slmll  closely  similar  to  that  of  parryii ;  audi- 
tal  bullae  averaging  slightly  smaller  and  less  inflated. 

Color. — Summer  pelage  (July)  :  Entire  top  of  head  (nose  to  occi- 
put) chestnut  or  bay;  sides  of  nose  tawny  or  ochraceous  tawny;  sides 
of  head,  neck,  and  shoulders  hazel  or  chestnut,  sometimes  washed 
with  ochraceous  buff  and  streaked  with  blackish;  ears  ochraceous 
tawny  on  both  surfaces;  dorsum  mars  brown,  more  or  less  overlaid 
with  pinkish  buff,  and  thickly  flecked  with  spots  of  buffy  white; 
anterior  sides  hazel;  posterior  sides  like  back  but  more  washed 
with  buffy ;  legs  and  feet  hazel ;  under  parts  hazel  or  amber  brown ; 
tail  above,  black,  more  or  less  overlaid  and  edged  with  cinnamon 
buff  or  tilleul  buff;  tail  beneath,  mikado  brown,  shaded  with 
cinnamon  buff  and  broadly  tipped  with  black.  Winter  pelage  (Octo- 
ber-April) :  Head  as  in  summer;  sides  of  nose  and  cheeks  cinnamon 
buff  or  ochraceous  buff;  nape  washed  with  cinnamon  buff  or  tawny; 
shoulders  and  fore  back  extensively  overlaid  with  pale  smoke  gray 
and  sides  heavily  washed  with  same;  legs  and  feet  tawny;  under 
parts  tawny  or  ochraceous  tawny,  sometimes  irregularly  shaded  with 
cinnamon  buff  and  buffy  white;  tail  hazel  beneath.  Melanisti^ 
phase :  About  20  percent  oi  the  specimens  examined  are  in  this  phase ; 
most  of  them  are  solid  blackish  brown,  more  or  less  sprinkled  with 
buffy  grayish  hairs  and  with  patches  of  bay  on  the  nose ;  several  are 
pure  black  on  the  entire  body,  with  a  few  brownish  hairs  at  the  tip 
of  the  tail ;  one  young  specimen  is  sprinkled  with  grayish  and  buffy 
spots  on  a  blackish  ground,  the  nose  and  feet  washed  with  brownish. 

Molt. — The  spring  molt  begins  in  late  June ;  specimens  taken  near 
Circle  June  27-30  show  new  pelage  covering  most  of  the  under  parts 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  105 

and  appearing  on  the  head,  shoulders,  and  front  legs;  others  taken 
the  same  dates  are  in  complete  siinmier  pelage.  A  specimen  from 
Fort  Yukon  taken  October  15,  1885,  was  apparently  acquiring  winter 
pelage,  but  the  method  of  molting  is  not  clearly  shown. 

Measurements. — Average  of  10  adult  males  from  near  Circle,  Alaska :  Total 
length,  456.4  (437-475)  ;  tail  vertebrae,  141.7  (131-153)  ;  hind  foot,  62.7  (61-65). 
Average  of  10  adult  females  from  same  locality:  433  (420-462)  ;  136  (126-147)  ; 
60.3  (57-63).  Skull:  Average  of  10  adult  males  from  Circle,  Alaska:  Greatest 
length,  63.1  (60.2-65.S)  ;  palatilar  length,  32.4  (31-34)  ;  zygomatic  breadth,  41.5 
(38.6-44.3)  ;  cranial  breadth,  24.5  (24-25.5)  ;  interorbital  breadth,  14  (12.7-15)  ; 
postorbital  constriction,  13.4  (12.5-14.8)  ;  length  of  nasals,  24  (23-25)  ;  maxillary 
tooth  row,  14  (13.3-14.6).  Average  of  10  adult  females  from  same  localitv : 
Greatest  length,  60.1  (58-61.8)  ;  palatilar  length,  29.9  (28-31)  ;  zygomatic 
breadth,  39.3  (37.4-42)  ;  cranial  breadth,  24  (23.3-25.1)  ;  interorbital  breadth, 
13  (12.3-14)  ;  postorbital  constriction,  13.6  (13-14.4)  ;  length  of  nasals,  22.6 
(21.8-23.4)  ;  maxillary  tooth  row,  13.9   (13.4^-15). 

Weight  of  males,  1^  to  2^  pounds  (average  about  1%  pounds)  ;  of  females, 
114  to  1%  pounds  (average  about  iy2  pounds)    (Osgood.  1909,  p.  23). 

Remarks. — The  Yukon  Valley  ground  squirrel  is  the  largest  known 
member  of  the  farinjii  group;  in  cranial  measurements  and  size  of 
hind  feet  it  averages  about  the  same  as  parryii  but  exceeds  it  in  length 
of  tail.  It  has  a  very  restricted  range  along  the  Yukon  River  and 
although  closely  related  to  parryii  apparently  does  not  intergrade 
with  it.  O.  J.  Murie,  in  ascending  the  Porcupine,  saw  no  squirrels 
until  near  the  mouth  of  Coleen  River;  specimens  taken  there  and  at 
Salmon  Trout  River  and  Rampart  House  are  nearly  typical  parryii^ 
showing  no  approach  to  osgoodi.  The  lower  limit  of  the  species  in 
the  Yukon  Valley  is  not  definitely  known,  but  the  upper  limit  has 
been  determined  by  Osgood  as  a  point  about  25  miles  above  Circle. 
No  ground  squirrels  of  any  kind  occur  along  the  Yukon  above  that 
point  until  near  the  mouth  of  Pelly  River,  where  the  much  smaller 
form,  C.  p.  plesiu^s.,  finds  its  lower  limit. 

Although  specimens  of  this  fine  squirrel  have  been  in  the  National 
Museum  collection  since  18G1,  when  Kennicott  collected  a  consider- 
able series,  they  were  not  recognized  as  distinct  from  parryii  until 
1900,  when  Merriam,  after  Osgood  had  recognized  it  in  the  field,  de- 
scribed the  species  as  new. 

Specimens  examined. — Total  number,  62,  as  follows : 

Alaska:  Yukon  River,  62  (Circle,  1;  Fort  Yukon,  3;  mouth  of  Porcupine  River, 
1 ;  ^'^  10  miles  above  Hess  Creek,  1 ;  20  miles  above  Circle,  55 ;  Yukon  Flats,  1 ) . 


**  Mus.  Comp.  Zool. 


106  NORTH  AMERICAN  FAUNA  [No.  56 

Subgenus  ICTIDOMYS  Allen 

[Characters  and  synonymy  on  p.  41] 

Key  to  Species  and  Subspecies 

c\  Dorsal  area  striped. 

6\  Larger ;  hind  foot  more  tlian  36  mm tridecemlineatus   (p.  107) 

&^  Smaller ;  hind  foot  less  than  36  mm. 
c\  Dark  stripes  distinctly  reddish  (russet or  mars  brown),  texensis  (p.  110) 
c^.  Dark  stripes  not  distinctly  reddish. 
d\  Colors  paler  (dark  stripes  snuff  brown,  walnut  brown,  or 
cinnamon  brown). 

e\  Larger  (skull  length  more  than  37  mm) arenicola  (p.  Ill) 

e^.  Smaller    (skull  length  less  than  37  mm) parvus   (p.  117) 

d^  Colors   darker    (dark   stripes   chestnut   brown,   mummy 
brown,  or  sepia). 

e\  Larger  (skull  length  more  than  37.5  mm) palUdus  (p.  112) 

e'.  Smaller  (skull  length  less  than  37.5  mm). 

f.  Dark  stripes  mummy  brown alleni    (p.   114) 

f.  Dark  stripes  chestnut  brown. 

f/\  Under  side  of  tail  russet nwnticola    (p.   116) 

g^.  Under  side  of  tail  chestnut  brown liollisteri  (p.  115) 

a'.  Dorsal  area  spotted. 
6\  Dorsal  spots  in  linear  series. 

c\  Larger ;  skull  length  more  than  45  mm mexicanus  (p.  119) 

cf.  Smaller;  skull  length  less  than  45  mm parvidens  (p.  121) 

b\  Dorsal  spots  not  in  linear  series. 

c^.  Dorsal  spots  and  under  parts  buffy perotensis   (p.  132) 

c^  Dorsal  spots  and  imder  parts  white. 
d\  Smaller  (skull  length  less  than  36.5  mm). 

e\  Dorsal  spots  distinct pratensis  (p.  128) 

er.  Dorsal  spots  not  distinct crypt ospilotus   (p.  130) 

d^  Larger  (skull  length  more  than  36.5  mm). 
e^.  Dorsal  spots  indistinct  or  obsolete. 

f.  Larger  (skull  length  39-42.5) major  (p.  126) 

f.  Smaller  (skull  length  37.7-39.9) ohsoletus  (p.  130) 

e'.  Dorsal  spots  distinct. 

f.  Dorsal  spots  smaller  (habitat  central  Mexico). 

g^.  Darker spllosoma  (p.  122) 

g-.  Paler pallescens    (p.  124) 

f.  Dorsal    si)Ots    larger     (habitat    United    States    and 
northern  Mexico). 

f/\  Smaller  (skull  length  less  than  38  mm) canescens  (p.  125) 

g\  Larger  (skull  length  more  than  38  mm). 

h^.  Audital  bullae  larger major  (p.  126) 

7i^.  Audital  bullae  smaller annectens  (p.  128) 

CITELLUS  TRIDECEMLINEATUS  GROUP 
CITELLUS    TRIDECEMLINEATUS    (Mitchill) 

[SynonjTuy  under  subspecies] 

Specific  characters. — Size  small  to  medium ;  hind  foot,  28-41  Trmn ; 
tail,  60-108;  skull  _  length,  34-45.8.  Skull  relatively  long,  narrow, 
and  weakly  built  (in  comparison  with  C.  toionsendii  mollis  or  C.  w. 
washingtoni),  the  brain  case  usually  longer  than  broad;  interorbital 
region  relatively  long,  the  supraorbital  margins  only  slightly  ele- 
vated; rostrum  long  and  tapering  gradually;  zygomata  rather  stout, 
but  not  widely  expanded ;  molarif orm  tooth  rows  slightly  convergent 
posteriorly;  audital  bullae  moderately  inflated,  the  external  meatus 
tube  short. 

Color. — Upper  parts  marked  with  a  series  of  alternating  light  and 
dark  longitudinal  stripes;  the  dark  stripes  are  usually  five  in  num- 
ber, brownish  or  blackish  in  color  and  extending  down  the  median 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  X07 

line  of  each  is  a  series  of  squarish  white  or  buffy  white  spots ;  alter- 
nating with  the  dark  stripes  are  about  six  narrower  whitish  stripes ; 
on  the  sides  are  several  additional,  more  or  less  indefinite,  stripes 
and  spots ;  in  some  races,  some  of  the  light  dorsal  stripes  are  broken 
into  spots. 

CITELLUS    TRIDECEMLINEATUS    TRIDECEMLINEATUS    (Mitchill) 

Thibteen-lined  Ground  Sqxjireei. 

Sciurus   tridecem-lmeatus  MitchiU,   Medical   Repository    (n.   s.)    6    (21)  :   248. 

1821. 
Arctomys   hoodii   Sabine,   Linn.    Soc.   London.   Trans.   13:   590,   1822    (Carlton 

House,    Saskatchewan). 
Arctomys  tridecemlineata  Harlan,  Fauna  Amer.,  p.  164,  1825. 
Spermophihis  tridecemlineatus  Audubon  and  Bachman,  Quad.  North  Amer.  1: 

294,  1849. 
[Citellus]  tridecimlineatus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  1904. 

.  Type. — None  designated.  "Brought  by  Professor  Douglas,  of  the 
United  States  Military  Academy,  from  the  region  bordering  the 
sources  of  the  river  Mississippi,  in  November  1820"  (Mitchill,  1.  c). 
Type  locality  fixed  in  "central  Minnesota"  by  J.  A.  Allen  (1895b, 
p.  338). 

Range. — Southern  parts  of  Alberta,  Saskatchewan,  and  Manitoba ; 
northern  Montana;  eastern  parts  of  North  Dakota,  South  Dakota, 
and  Nebraska ;  northeastern  Kansas ;  northern  Missouri ;  all  of  Iowa ; 
most  of  Minnesota  and  Wisconsin;  Lower  Peninsula  of  Michigan; 
northern  parts  of  Illinois  and  Indiana;  and  southwestern  Ohio. 
North  to  Athabaska  Landing,  Alberta;  east  to  Fairfield  County, 
Ohio;  south  to  central  Kansas;  west  to  Red  Deer,  Alberta,  and  St. 
Mary  Lake,  Mont.  (fig.  9).  Zonal  range:  Transition  and  Upper 
Austral. 

External  characters. — Size  large ;  coloration  dark ;  all  light  stripes 
continuous,  not  broken  into  spots;  larger  than  C.  t.  texensis  and 
averaging  more  blackish  (less  reddish).  Occasional  specimens  in 
winter  pelage  are  almost  as  reddish  as  texensis^  but  always  larger. 

Cranial  characters. — Skull  large  (for  the  species) ;  somewhat  sim- 
ilar to  that  of  G.  tvashingtoni  washingtoni  but  differing  in  the  char- 
acters of  the  subgenus;  narrower  brain  case;  longer  rostrum; 
zygomata  less  spreading;  postorbital  processes  shorter  and  slenderer; 
anterior  premolar  relatively  smaller;  upper  incisors  shorter  and 
stouter. 

Color. — Swnmer  pelage  (July-September)  :  Sides  of  nose  cin- 
namon buff;  eye  ring  pinkish  buff;  cheeks  mixed  fuscous  and  cin- 
namon buff;  ear  rim  and  sides  of  neck  cinnamon  or  ochraceous 
tawny;  dark  dorsal  stripes  dark  fuscous  or  fuscous  black,  the  five 
median  ones  each  with  a  row  of  squarish  or  rectangular  buffy  white 
spots  down  the  center:  light  dorsal  stripes  buffy  white;  front  legs 
and  feet  cinnamon  buff;  hind  legs  mikado  brown  or  russet,  the  feet 
cinnamon  buff;  tail  above,  fuscous  black,  mixed  with  sayal  brown 
and  bordered  with  pinkish  buff;  tail  beneath,  russet  or  mikado 
brown  at  base,  shading  to  ochraceous  buff  or  cinnamon  buff  toward 
tip,  more  or  less  mixed,  especially  near  tip,  with  fuscous  black; 
lower  sides  cinnamon  buff,  shading  to  pinkish  buff  on  throat  and 
belly;  chin  creamy  white.  Winter  pelage  (April  and  May)  :  Similar 
to  the  summer  pelage  but  dark  dorsal  stripes  mars  brown  or  chest- 


108 


NORTH  AMERICAN  FAUNA 


[No.  56 


nut  brown,  and  light  dorsal  stripes  creamy  white  rather  than  buffy 
white. 

Measurements. — Average  of  10  adult  males  from  Fort  Snelling  and  Elk 
River,  Minn.:  Total  length,  284.9  (274-297);  tail  vertebrae,  104.7  (90-132); 
liind  foot,  39.8  (38-41).  Average  of  10  adult  females  from  Minnesota  and 
Wisconsin:  Total  length,  267.9  (239-285)  ;  tail  vertebrae,  93.6  (80-103)  ;  hind 
foot,  37.3  (35-40).  Skull:  Average  of  10  adults  from  Elk  River  and  Fort 
Snelling,  Minn.:  Greatest  length,  44  (43.2-45.8)  ;  palatilar  length,  20.5  (20-21)  ; 


Figure  9. — Distribution  of  the  subspecies  of  Citellus  tridecemlineatus:  1,  C.  t.  tridecemli- 
neatus;  2,  C  t.  pallidus ;  3,  G.  t  texensis;  4,  C.  t.  arenicola;  5,  C.  t.  alleni:  6,  C.  t. 
parvus;  7,  C.  t.  hollisteri;  8,  0.  t.  monticola. 

zygomatic  breadth,  25.1  (24.4-26.4)  ;  cranial  breadth,  17.6  (17.3-18)  ;  inter- 
orbital  breadth,  8.1  (7.7-9)  ;  postorbital  constriction,  11  (10.2-11.4)  ;  length 
of  nasals,  15.3  (14.3-16.8)  ;  maxillary  tooth  row,  7.9  (7.6-S.4).  Average  of 
8  adult  females  from  same  localities:  Greatest  length,  42.7  (41.2-44.2)  ; 
palatilar  length,  19.7  (18.5-21)  ;  zygomatic  breadth,  24.3  (23-25.5)  ;  cranial 
breadth,  17.3  (16.3-18.1)  ;  interorbital  breadth,  8.3  (7.3-9.1)  ;  postorbital  con- 
striction, 11.1  (10.5-11.8)  ;  length  of  nasals,  14.9  (14.2-15.6)  ;  maxillary  tooth 
row,  7.8  (7.4-8.2). 

V/eiffht. — Wade   (1930,  p.  170)   gives  the  weights  of  four  males  as  ranging 
from  170-243  g ;  of  four  females,  from  14rt-211  g. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  109 

Remarks. — The  typical  race  of  the  striped  ground  squirrel  has 
an  extensive  range  in  the  upper  Mississippi  Valley  and  the  northern 
plains  and  is  an  abundant  animal  over  most  of  its  range.  Consid- 
erable individual  and  seasonal  variation  is  shown  in  nearly  every 
series  of  this  race,  specimens  taken  in  midsummer  being  the  darkest 
and  those  taken  in  late  spring  decidedly  paler  and  more  tawny  (less 
brownish).  Specimens  from  near  the  northern  limits  of  its  range 
(Edmonton,  Alberta)  are  not  appreciably  different  from  typical 
specimens,  but  those  from  northwestern  Montana  (St.  Mary  Lake 
and  Choteau)  are  somewhat  paler,  thus  showing  approach  to  C.  t. 
■pallidus.  Intergradation  with  the  latter  is  shown  also,  by  numerous 
specimens  from  central  North  Dakota,  South  Dakota,  Nebraska,  and 
Kansas.  A  large  series  from  Knoxville,  Iowa,  shows  approach  to 
texeTisis  in  slightly  smaller  size  and  in  the  reddish  tone  of  the  under 
side  of  the  tail.  The  under  parts  are  more  strongly  buffy  than  in 
either  tridecemlineatus  or  texensis.  A  small  series  from  Onaga, 
-  Kans.,  is  typical.  The  large  series  examined  from  Leavenworth  and 
Douglas  Counties,  Kans.,  is  intermediate  between  tridecemlineatus 
and  texensis.^  but  a  little  nearer  to  the  former;  the  one  summer  speci- 
men is  clearly  tridecemlineatus;  the  skulls  are  intermediate  in  size. 
Specimens  examined. — Total  number,  44.5,  as  follows: 

Alberta:  Chief  Mountain  Lake,  1;  Red  Deer,  3;  South  Edmonton,  5;  Sturgeon 
River  (25  miles  north  of  Eclmontoi!).  1. 

Illinois:  Chicago,  15;"  Kansas,  1;  Riverdale  (Cook  County),  1;"  Warsaw,  1; 
Waukegan,  1;"  Wheatland  To'.vnshiri  (Will  County).  1."' 

Indiana:  La  Fayette  (8  miles  east),  1;  Lake  Village  (Newton  County),  1;" 
Logansport,  1;^  Montezuma  (Parke  County).  I:*"  Notre  Dame.  2;*^  Pine 
Station  (Lake  County),  1;  Roseland  (St.  Joseph  County),  1;"  Ro.val  Cen- 
ter, 2;  South  Bend,  1;"  Wahash  Township  (Tippecanoe  County),  1. 

Iowa:  Ames,  1;**  Burlington,  22;  Knoxville,  16;  Luxemhurg,  1.** 

Kansas:  Douglas  County,  12;**  Fort  Leavenworth,  1;  Fort  Riley,  1;  Lawrence, 
8 ;"  *°  Leavenworth,  5  f  Onaga,  5. 

Manitoba:  Carherry.  34;  Red  River  Settlement,  1. 

Michigan:  Alma,  2;''  Ann  Arbor,  13;*"  Birchwood  Beach  (Berrien  County),  1;" 
Boyne  Falls  (Charlevoix  County),  1;'^  Boyne  Valley  (Charlevoix  County), 
1;"  Byron  (Shiawassee  County),  2;*^  Chelsea,  1:*^  Douglas  Lake  (Cheboy- 
gan County),  1;**  Harbert  (Berrien  County),  1  ;"  Higgins  Lake  (Roscom- 
mon County),  1;"  Le  Roy  (Osceola  County).  2;^  Lucerne  (Oscoda  County), 
1  f^  Manchester,  1 ;"  Montmorency  County,  2  ;*^  Otsego  County,  1 ;"  Portage 
Lake  (Washtenaw  County),  3;*^'"  Warren  Preserve  (Berrien  County),  2;** 
Waterloo  (Jackson  County).  1.** 

Minnesota:  Brown  Valley,  3;  Elk  River,  21;  Fort  Snelling  (Hennepin  County), 
4;"  Geneva  Lake  (Freeborn  County),  1:  Germantown  (Marshall  County), 
1;  Goodhue,  3;"  Hutchinson,  1;  Ortonville,  2;  Princeton  (Benton  County), 
1;  Waseca  County,  1.*^ 

Montana:  Bear  Paw  Mountains  (20  miles  southeast  of  Port  Assiniboine) ,  1; 
Blackfoot  Agency  (Glacier  County),  1;  Choteau.  1;  Johnson  Lake  (Roose- 
velt County),  1;  St.  Mary  Lake.  3:  St.  Mary  River  (15  miles  below  St. 
Mary  Lake),  1:  Zortman   (Phillips  County),  1. 

Nebraska:  Broken  Bow,  1;"  Columbus,  4;  Glen  (Sioux  County),  1;**  North 
Platte,  2;»*  Verdigris,  1. 

North  Dakota:  Bismarck,  2;  Bottineau,  1;  Braddock,  2-^  Buford  (Williams 
County).  3;  Casselton,  1;  Crosby.  1;  Dawson  (Kidder  County),  1:  Devils 
Lake,  1  ;'='  Drayton,  1 ;  Ellendale,  1 ;  Fairmount,  7 :  Fargo,  3 ;  Fort  Berthold 
(McLean  County),  1;  Fort  Buford  (Williams  County),  3;  Grand  Forks.  4; 
Grafton,  3;  Grinnell  (Williams  County),  1;  Hankinson,  2;  Harwood  (Cass 
County),  1;  Lidgerwood,  1;  Ludden  (Dickey  County),  2;  Minot,  4;"^  Oakes, 
5;  Old  Fort  Union  (near  Buford),  4;  Pembina.  9;  Portland,  1;  Stark- 
weather, 2;  Steele,  8;"=  Streeter,  1;  Stump  Lake,  2;  Towner,  3;  Turtle 
Creek  (near  Washburn),  3;  Valley  City.  3;  Walhalla,  1;  Washburn,  1; 
Yellowstone  River  (mouth),  2;  Zeeland,  1. 

See  footnotes  on  page  110. 


210  NORTH  AMERICAN  FAUNA  iNo.  56 

Ohio:  Bainbridge  (Ross  County),  9;^'  Circleville,  1;*"  Lancaster,  6. 

Saskatchewan :  Grenfell,  1 ;  Indian  Head,  3 ;  Livelong,  2 ; ""  Prince  Albert,  2 ;  ^ 
Wingard,  4. 

South  Dakota:  Plandreau,  2;  Fort  Randall  (Gregory  County),  1;  Mitchell,  2; 
Pierre,  2 ;  Lake  Traverse,  5 ;  Vermillion,  1 ;  "^  White  Lake  (Avirora  County),  1. 

Wisconsin:  Bay  Settlement  (Brown  County),  3;**  Beaver  Dam,  14;°^  Ben- 
derville  (Brown  County),  1;^  Bussyville  (  =  Sumner,  Jefferson  County),  1; 
Camp  Douglas  (Juneau  County),  1;  Clark  County,  2;^^  Danbury  (Burnett 
County),  2;  Delavan,  1;  Devils  Lake  (Sauk  County),  i;  Endeavor,  2; 
Friendship,  2;  Green  Lake,  4;  Herbster  (Bayfield  County),  2;  Holcombe 
(Chippewa  County),  2;  Kelly  Lake  (Oconto  County),  1;  La  Crosse,  2;  Long 
Lake  (Washburn  County),  1;  Mather  (Juneau  County),  2;  Namakagon 
Lake  (Bayfield  County),  1;  Nashotah  (Waukesha  County),  2;  Orienta 
(Bayfield  County),  2;  Prescott,  1;  Racine,  7;  Rib  Hill  (Marathon  County), 
6;  Solon  Springs,  2;  Stevens  Point,  1;  Three  Falls  (15  miles  west  of 
Crivitz,  Marinette  County),  2f*  Wauzeka  (Crawford  County),  1. 

CITELLUS  TRIDBCEMLINEATUS  TEXENSIS   (Mebriam) 

Texas  Stetped  Ground  Squierel  , 

Sperniophilus  tridecemlineatus  texensis  Merriam,  Biol.  Soc.  Wash.  Proc.  12 :  71, 

Mar.  24,  1898. 
Sperrnophilus   (Ictldomt/s)   tridecemlineatus  dadius  Bangs,  New  England  Zool. 

Club  Proc.  1:  1,  1899  (Stotesbury,  Mo.). 
[Citellus  tridecemlineatus']  texensis  Trouessart,  Cat.  Mamm.,  Sup.,  p.  342,  1904. 

Type. — Collected  at  Gainesville,  Tex.,  April  15,  1886,  by  George  H. 
Ragsdale;  male  adult,  skin  and  skull,  no.  186471,  U.  S.  Natl.  Mus. 
(formerly  no.  f|^,  Merriam  collection). 

Range. — Prairie  region  of  middle  eastern  portions  of  Texas  and 
Oklahoma;  north  to  southeastern  Kansas  (Cairo  and  Garden  Plain) ; 
east  to  southwestern  Missouri  (Stotesbury  and  Golden  City) ;  south 
to  Bee  County,  Tex. ;  west  to  Vernon,  Tex.,  and  Mount  Scott,  Wichita 
Mountains,  Okla.  (fig.  9).    Zonal  range:  Lower  Austral. 

Extejmal  characters. — Similar  to  C.  t.  tridecemlineatus  but  smaller, 
with  upper  parts  and  under  side  of  tail  paler  and  more  reddish. 

Cranial  characters. — Skull  similar  to  that  of  tridecemlineatus  but 
smaller,  and  relatively  broader  across  brain  case  and  zygomata. 

Color. — Winter  pelage  (April)  :  Dark  dorsal  stripes  russet  or  mars 
brown;  light  stripes  and  spots  creamy  white;  eye  ring  buffy  white; 
lower  sides  and  under  parts  cream  color  or  pinkish  buff;  fore  and 
hind  feet  pinkish  buff  or  buffy  white;  tail  above,  same  color  at  base 
as  the  back,  but  more  or  less  overlaid  with  whitish  hairs,  and  shading 
to  cimiamon  buff  on  distal  portion,  the  hairs  on  sides  of  tail  tilleul 
buff  at  tips  with  a  subterminal  band  of  fuscous  black ;  tail  beneath, 
russet  in  center,  edged  and  more  or  less  overlaid  with  tilleul  buff. 
Summer  pelage  (August)  :  Dark  strikes  chestnut  brown;  light  stripes 
buffy  white  to  pale  cinnamon  buff. 

Measurements. — ^Average  of  10  adults  (4  males,  6  females)  from  Texas  (Ver- 
non, Wichita  Falls,  Henrietta,  Gainesville)  :  Total  length,  258  (227-267)  ;  tail 
vertebrae,  92  (80-102);  hind  foot,  34  (33-36).  Slvull:  Average  of  11  adults 
(4  males,  7  females)   from  Texas   (Gainesville,  Vernon,  Henrietta,  Richmond, 


*2  Univ.  Michigan  Mus.  Zool. 

*3  p.  F.  Hickie  collection. 

^  Univ.  of  Notre  Dame. 

^Kansas  Univ.  Mi.is.  Nat.  Hist. 

*"  Cornell  Univ.  Mus. 

®^Amer.  Mus.  Nat.  Hist. 

**  Univ.  Nebraska. 

89  Cleveland  Mus.  Nat.  Hist. 

0"  William  T.  Shaw  collection. 

»i  South  Dakota  State  Biol.  Survey. 

»=  Field  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  m 

Wichita  Falls)  :  Greatest  length,  40.4  (39.5-42.1)  ;  palatilar  length,  19  (18.2-20)  ; 
zygomatic  breadth,  24.2  (23.1-25.8)  ;  cranial  breadth,  17.8  (16.9-18.9)  ;  inter- 
orbital  breadth,  8  (7-8.4)  ;  postorbital  constriction,  11.9  (10.7-12.6)  ;  length  of 
nasals,  14.3  (13.2-15.6)  ;  maxillary  tooth  row,  7.5  (7.3-8). 

Remarks. — The  Texas  ground  squirrel  is  a  well-marked  form, 
characterized  especially  by  its  reddish  coloration.  Specimens  from 
Kiowa  and  Cairo,  Kans.,  and  Alva,  Okla,,  are  paler  than  typical 
specimens,  thus  showing  apf>roach  to  G .  t.  arenicola.  A  single  speci- 
men from  Dimmitt,  Tex.,  seems  referable  here,  although  on  geo- 
graphical grounds  it  should  be  within  the  range  of  arenicola. 

The  series  from  Stotesbury,  Mo.,  which  formed  the  basis  of 
'"'"'badius'''  of  Bangs  is  closely  similar  in  color  to  texensis.,  winter 
specimens  being  practically  indistinguishable ;  summer  specimens  are 
slightly  darker  (more  blackish)  and  the  skulls  are  slightly  larger. 
The  series  is  thus  intermediate  between  texensis  and  tridecemlineatiis 
but  with  too  slight  characters  for  recognition  by  name. 

Specimens  examined. — Total  number,  72,  as  follows: 

Kansas :  Anderson  County,  1 ;  "  Belle  Plaine,  2 ;  Columbus,  1 ;  °^  Garden  Plain, 
1 ;   Independence,   2."^ 

Missouri:  Golden  City,  5;  Stotesbury  (Vernon  County),  12;"*  Washburn  (Barry 
County),  6. 

Oklahoma:  Apache,  1;  Arnettville,  1;*°  Fort  Reno  (Canadian  County),  2;  Law- 
ton,  1;  Mount  Scott  P.  O.  (Comanche  County),  14;  Noble,  2;  '^  Norman,  2:*' 
Orlando,  3. 

Texas:  Cooke  County,  1;  Gainesville,  2;  Henrietta,  3;  Richmond,  4;  Vernon, 
4;  Wichita  Falls,  2. 

CITELLUS  TRIDECEMLINEATUS  ARENICOLA  Howell 

Sandhill  Stetped  Ground  Squierkl 

Citellus  tridecemlineatus  arenicola  Howell,  Biol.  Soc.  Wash.  Proc.  41:  213, 
Dec.  18,  1928. 

Type. — Collected  at  Pendennis,  Kans.,  April  22,  1897,  by  J.  Aldeii 
Loring;  male  adult,  skin  and  skull;  no.  87686,  U.  S.  Natl.  Mus.  (Bio- 
logical Survey  collection)  (orig.  no.  3988). 

Range. — Southwestern  Kansas,  eastern  Colorado,  northwestern 
Texas,  northwestern  Oklahoma,  and  eastern  New  Mexico;  north  to 
Logan  County,  Colo. ;  east  to  Barber  County,  Kans. ;  south  to  Lub- 
bock, Tex.,  and  Roswell,  N.  Mex. ;  west  to  Lincoln  County,  N.  Mex. 
(fig.  9).    Zonal  range:  Upper  Sonoran. 

External  characters. — Similar  to  G.  t.  pallidus.,  but  smaller  and 
paler,  the  dark  dorsal  stripes  snuff  brown  instead  of  sepia;  similar, 
also,  to  G.  t.  texensis.,  but  smaller  and  much  paler. 

Granial  characters. — Skull  similar  to  that  of  pallidus.,  but  aver- 
aging slightly  smaller,  except  in  breadth  of  the  cranium;  nasals 
shorter. 

Golor. — Winter  pelage  (April  23)  :  Dark  dorsal  stripes  snuff 
brown  or  Front's  brown ;  light  dorsal  stripes  and  spots  white,  some- 
times faintly  washed  v/ith  pale  buff;  tail  above,  cinnamon  buff, 
shaded  with  bister,  becoming  fuscous  or  fuscous  black  on  distal  end, 
strongly  margined  with  buffy  white;  tail  beneath,  tawny  on  median 
basal  portion,  shading  to  cinnamon  on  distal  portion,  edged  with 
fuscous  black  and  tipped  with  buffy  white;  feet,  under  parts,  and 


•*  K.insas  Univ.  Mus.  Nat.  Hist. 
•*Mus.  Comp.  Zool. 
•»  Field  Mus.  Nat.  Hist. 


2]^2  NORTH  AMERICAN  FAUNA  [No.  56 

sides  buffy  white.  Summer  pelage  (Lipscomb,  Tex.,  July  8)  :  Dark 
dorsal  stripes  cinnamon  brown ;  light  stripes  tilleul  buff ;  under  parts 
and  sides  dull  buffy  white ;  hind  feet  pinJkish  buff ;  tail  as  in  wmter 
pelage. 

Measurements. — Average  of  8  adults  (4  males,  4  females)  from  type  locality: 
Total  length,  238  (214-295)  ;  tail  vertebrae,  77.7  (71-83)  ;  hind  foot,  32.2 
(31-34).  Skull:  Average  of  8  adult  males  (3  from  Pendennls,  5  from  Morton 
County,  Kans.)  :  Greatest  length,  39.1  (38.3^0.3)  ;  palatilar  length,  17.9  (17.5- 
18.5)  ;  zygomatic  breadth,  23.2  (22.6-24.3)  ;  cranial  breadth,  17.2  (16.8-17.6)  ;  in- 
terorbital  breadth,  8.1  (7.4-8.9)  ;  postorbital  constriction,  12  (11.6-12.5)  ;  length 
of  nasals,  13.9  (13.2-14.9)  ;  maxillary  tooth  tow,  7.2  (6.8-7.7).  Average  of  8 
adult  females  from  same  localities:  Greatest  length,  38.1  (37.3-39.7)  ;  palatilar 
length,  17.7  (17.1-18)  ;  zygomatic  breadth,  22.7  (21.9-23.4)  ;  cranial  breadth, 
17  (16.2-17.8)  ;  interorbital  breadth,  7.6  (7-8.2)  ;  postorbital  constriction,  13.5 
(13-14.4)  ;  length  of  nasals,  13.5  (13-14.4)  ;  maxillary  tooth  row,  7  (6.7-7.2). 

Remarks. — This  race  is  the  palest  of  all  the  forms  of  this  species. 
The  dorsal  stripes  are  more  reddish  in  tone  than  in  palUdus,  m  this 
respect  showing  approach  to  texensis.  Intergradation  with  pallidus 
occurs  in  eastern  Colorado,  northwestern  Kansas,  and  western  Ne- 
braska. A  large  series  from  Baca  County,  southeastern  Colorado,  is 
typical  of  arenicola  in  color,  but  the  skulls  are  like  those  of  paUidus. 

Specimens  examined. — Total  number,  110,  as  follows : 

Colorado:  Akron,  1 ; '^  Eureka  Hill  (Cheyenne  County),  1;  Greeley,  1;  Kit 
Carson  County,  1;'"  Leroy  (Logan  County),  1;  Monon  (Baca  County),  6;" 
Springfield  (Baca  County),  8; "'  Sterling,  5;  Tuttle  (Kit  Carson  County),  1 ; 
Washington  County,  2;'"'"MVray,  3;'°  Wray  (20  miles  northwest),  1.'' 

Kansas:  Banner  (Gove  County),  2;"^  Cairo  (Pratt  County),  1;  Clark  County, 
1;*"  Coolidge  (Hamilton  County),  1;"*  Fowler  (Meade  County),  2;°^  Grin- 
nell  (Gove  County),  2 ;  ^  Kiowa,  4;  Medicine  Lodge  1 ;  Morton  County,  13 ;  ^ 
Oaklev,  1;  Oanica  (Kearney  County),  2;"*  Pendennis  (Lane  County),  10; 
Phillipsburg,  1 ;  '^^  Scott  City,  3  ;  Wallace  (Wallace  County),  1.°* 

New  Mexico:  Cabra  Springs  (6  miles  north,  San  Miguel  County),  1;  Chico 
Springs  (Colfax  County),  1;  Clayton,  1;  Folsom,  1;  Loveless  Lake  (10  miles 
northwest  of  Capitan  Mountains,  Lincoln  County),  1;  Preston  (Colfax 
County),  1;  Roswell,  1;  San  Jon  (Quay  County),  5;^  Tucumcari  (25  miles 
west),  1. 

Oklahoma:  Alva,  4;'  Woodward,  3. 

Texas:  Dimmitt  (20  miles  south),  1;  Lipscomb,  3;  Lubbock,  2;  Mobeetie,  1; 
Texliue  (20  miles  east),  1;  Washburn,  6. 

CITELLUS  TRIDECEMLINEATUS  PALLIDUS   (Aixen) 

Palud  Striped  Geound  Squxrbei, 

[SpermopMlus    trldecemlineatus]    var.    pallidus    Allen,    Monog.    North    Amer. 

Rodentia,  p.  872,  1877. 
[Citellus  tridecimlineatus']  palUdus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  1904. 
SpermopMlus  tridecemlineatus  oUvaceus  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  7: 

337,  1895  (Custer,  S.  Dak.), 

Type. — None  designated;  type  locality,  mouth  of  the  Yellowstone 
River,  Mont.* 

Range. — Plains  of  Montana  east  of  the  Rocky  Mountains,  eastern 
Wyoming,   northeastern    Colorado,   northwestern    Kansas,    western 


**  Univ.  Micbigan  Mus.  Zool. 
^'  E.  R.  Warren  collection. 
'8  Kansas  Univ.  Mus.  Nat.  Hist. 
«9  Colorado  Mus.  Nat.  Hist. 

*  Kansas  State  Agr.  College. 
2  Cleveland  Mus.  Nat.  Hist. 

8  Two  in  Field  IMus.  Nat.  Hist. 

*  Cf .  Allen  (1895b,  p.  338)  -wliere  the  type  region  is  designated  as  "plains  of  the  Lower 
Yellowstone  River."  In  order  to  fix  the  type  locality  more  definitely,  specimen  number 
16237,  U.  S.  National  Museum,  taken  Aug.  18,  1857,  at  the  mouth  of  the  Yellowstone, 
by  F.  V.  Hayden,  is  here  selected  as  a  lectotype. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  1X3 

parts  of  Nebraska  and  South  Dakota,  and  southwestern  North 
Dakota;  north  to  the  Missouri  River  in  Montana,  east  to  the  Mis- 
souri in  North  Dakota,  and  to  about  the  100th  meridian  in  Nebraska 
and  Kansas;  south  to  Ellis  and  Trego  Counties,  Kans.,  and  Colorado 
Springs,  Colo. ;  west  to  Casper  and  Laramie,  Wyo.,  and  to  Canadian 
Creek  (North  Park)  and  Como  (South  Park),  Colo.  (fig.  9). 
Zonal  range :  Upper  Sonoran  and  Transition. 

External  characters. — Similar  to  G.  t.  tridecemlineatus  but  smaller 
and  paler. 

Cranial  characters. — Skull  similar  to  that  of  tridecemlineatus,  but 
decidedly  smaller  and  with  relatively  broader  rostrum  and  brain 
case. 

Color. — Summer  pelage  (August  and  September) :  Dark  dorsal 
stripes  sepia ;  light  stripes  and  spots  grayish  white  or  ca,rtridge  buff ; 
front  and  sides  of  face  pinkish  buff,  washed  with  pinkish  cinnamon 
on  nose;  front  feet  pinkish  buff;  hind  feet  cartridge  buff,  the  legs 
.cinnamon  buff  or  washed  vrith  cinnamon  or  clay  color;  tail  above  and 
beneath,  cinnamon  buff,  mixed  with  fuscous  black  and  overlaid  with 
pinkish  buff' ;  under  parts  and  lower  sides  cartridge  buff,  shaded  with 
pinkish  buff.  Winter  pelage  (May  21)  :  Very  similar  to  the  summer 
pelage,  but  light  dorsal  stripes  and  spots  more  whitish  (less  buffy) ; 
sides  of  face,  neck,  and  body  pinkish  buff. 

Measurements. — Average  of  10  adult  males  from  eastern  Montana:  Total 
length,  244.2  (214-255);  tail  vertebrae,  80.7  (60-91);  hind  foot,  32.9  (31-35). 
Average  of  10  adult  females  from  same  section:  Total  length,  232.5  (220-252)  ; 
tail  vertebrae,  82.2  (76-91)  ;  hind  foot,  32.3  (31-35).  Skull:  Average  of  7  adult 
males  from  eastern  Montana:  Greatest  length,  39.5  (38-42.1)  ;  palatilar  length, 
18.5  (17.5-19.5)  ;  zygomatic  breadth,  23.2  (22.3^24.6)  ;  cranial  breadth,  17.1 
(10.6-18.3)  ;  interorbital  breadth,  7.6  (7.2-8.4)  ;  postorbital  constriction,  11 
(10-11.7)  ;  length  of  nasals,  14.8  (14-15.4)  ;  maxillary  tooth  row,  7  (6.7-7.3). 
Average  of  10  adult  female.s  from  same  section :  Greatest  length,  38.8  (30.4- 
41.3)  ;  palatilar  length,  18.2  (17-19.8)  ;  zygomatic  breadth,  23.1  (21.9-24.7)  ; 
cranial  breadth,  16.8  (15.8-17.9)  ;  interorbital  breadth,  7.3  (6.6-7.8)  ;  postorbital 
constriction,  10.6  (9.9-11.3)  ;  length  of  nasals,  14.3  (13.4-15.7)  ;  maxillary  tooth 
row,  7  (6.5-7.4). 

Remarks. — The  pallid  ground  squirrel  is  distinctly  smaller  and 
paler  than  the  typical  race,  but  larger  and  darker  than  C.  t.  parvus 
and  C.  t.  arenicola.  It  was  described  from  the  plains  of  the  lower 
Yellowstone,  at  the  northern  edge  of  its  raiige.  On  the  north  side  of 
the  Missouri  River,  directly  opposite  the  mouth  of  the  Yellowstone, 
the  squirrels  are  darker  and  are  referable  to  tridecemlineatus.  In- 
tergradation  with  the  typical  race  occurs  over  a  considerable  strip  of 
country  in  the  central  parts  of  North  Dakota.  South  Dakota,  Ne- 
braska, and  Kansas.  Southward,  in  eastern  Colorado  and  north- 
western Kansas,  this  race  intergrades  with  arenicola.  Doubtless  it 
intergrades  also  with  C.  t.  alleni  in  the  foothills  of  the  Bighorn 
Mountains,  but  no  specimens  are  available  from  that  section.  Four 
specimens  from  Casper,  Wyo.,  are  typical  of  pallidus  in  color,  but 
the  skulls  are  smaller  and  more  like  those  of  parvus. 

The  type  series  of  ''^olivaceus''''  from  Custer,  S.  Dak.,  has  been  com- 
pared with  a  large  series  of  typical  pallidus  and  is  found  to  agree 
closely  with  it. 


154970—38 8 


11/^  '  NORTH  AMERICAN  FAUNA  [No.  56 

Specimens  examined. — ^Total  number,  314,  as  follows : 

Colorado:  Barr  (Adams  County),  3;°  Boulder,  1;  Canadian  Creek  (Jackson 
County),  5;  Colorado  Springs,  20;'^  Como  (Park  County),  5;  Deer  Trail 
Arapahoe  County),  1;^  Denver,  2;  Divide  (Teller  County),  6/  Elbert  (6 
miles  south),  1;'  Elbert  County  (between  Mattison  and  Resolis),  1;"  Elk- 
horn  (Larimer  County),  1;  Fort  Collins,  1;  Golden,  2;  Horsetail  Creek 
(Weld  County),  5;^  Loveland,  22;  Manitou,  1;'^  Pav^nee  Buttes  (Weld 
County),  2;  Puma  City  (Park  County),  1;*  Simla  (12  miles  east),  1;^ 
Tarryall  Creek  (Park  County),  1;^  Valmont  (Boulder  County),  1. 

Kansas:  Atwood  (10  miles  east  and  27  miles  west) ,  2 ;  *  Colby,  1 ;  Ellis,  1 ;  Hays, 
1;  Logan  County,  3*;  North  Solomon  River  (Graham  County),  1;  Solomon 
River  (Graham  County),  1;  Trego  County,  10;  Woodston  (Rooks 
County),  3.' 

Montana:  Albion  (Carter  County),  1;  Baker  (10  miles  north,  4;  Billings,  1; 
Broadus  (10  miles  northeast),  1;  Capitol  (Carter  County),  2;  Cohagen 
(16  miles  southeast,  Garfield  County),  2;  Crow  Agency  (Bighorn  County), 
5;  Fort  Custer  (Bighorn  County),  2;  Intake  (Dawson  County),  ?.;  Little 
Bighorn  River  (2  miles  north  of  Wyoming  border),  1;  Little  Dry  Creek 
(Garfield  County),  1;  Medicine  Rocks  (Carter  County),  3;  Melstone  (Mus- 
selshell County),  1;  Pilgrim  Creek  (10  miles  east  of  Broadus),  1;  Piney 
Buttes,  1;  Powderville  (Powder  River  County),  6;  Pryor  Mountains  (Car- 
bon County),  1;  Roy  (20  miles  northeast,  Fergus  County),  1;  Terry,  1; 
Tilyou  Ranch  (26  miles  above  mouth  of  Yellowstone  River),  3;  Wibaux 
(17  miles  south  and  17  miles  west),  11. 

Nebraska:  Antioch  (Sheridan  County),  2;'  Beaver  City,  1;  Birdwood  Creek 
(Lincoln  County),  p.;  Blue  River  (near  head,  Hamilton  County),  1;  Calla- 
way, 1;  Cody  (Cherry  County),  1;  Eustis  (Frontier  County),  1;  Gavin 
Custer  County),  1 ; '^  Gothenberg,  1;  Grand  Island,  1;*  Hackberry  Lake 
(Cherry  County),  2;^  Homerville  (Gosper  County),  1;  Kelso  (Hooker 
County),  2;'  Kennedy  (Cherry  County),  8;  Myrtle  (Lincoln  County),  1; 
Niobrara  River  (Cherry  and  Sheridan  Counties),  2;  North  Platte,  6;  O'Fal- 
lons  Bluff  (Lincoln  County),  1;  Sidney,  1;  Valentine,  21. 

North  Dakota:  Fort  Clark  (Oliver  County),  4;  Glen  UUin  (Morton  County),  6; 
Heart  River  (at  head),  1;  Mandan,  2;  Mikkelson  (Billings  County),  1; 
Oakdale  (Dunn  County),  2;  Sentinel  Butte  (Valley  County),  2. 

South  Dakota:  Ai-dmore  (Fall  River  County),  1;  Buffalo  Gap  (Custer  County), 
2;  Buffalo  Valley  (Stanley  County),  I;  Bull  Springs  (near  Custer),  10;" 
Custer,  21:'"  Diamond  S  Ranch  (near  Rapid  City),  1;*  Elk  Mountain 
(Custer  County),  1;  Minichaduza  River  (Todd  County),  1;  Pactola  (Pen- 
nington County),  1;  Pine  Ridge  Agency  (Shannon  County),  1;  Spring  Creek 
(Custer  County),  1." 

Wyoming:  Bear  Lodge  Mountains  (Crook  County),  1;  Casper,  4;  Cassa  (Platte 
County),  1;  Cheyenne,  13;  Chugwater  (Platte  County),  3;*  Douglas,  3; 
Fort  Laramie,  1;  Fort  Russell  (Laramie  County),  1;  Islay  (Laramie 
County),  1;  Medicine  Bow  Mountains,  1;  Moorcroft  (Crook  County),  6; 
Newcastle  (and  25  miles  southwest),  3;  Pine  Bluffs  (Laramie  County),  3; 
Spoon  Butte  (Goshen  County),  J;  Sundance,  1. 

CITELLUS  TRIDECEMLINEATUS  ALLENI   (Mebeiam) 

Bighorn  Stetpei)  Gkound  Sqxjibeel 

Spermophilus  tridecemlineatus  alleni  Merriam,  Biol.  Soc.  Wash.  Proc.  12:  71, 

Mar.  24,  1898. 
[Citellus  tridecimlineatus']  alleni  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  1904. 

Type. — Collected  near  head  of  Canyon  Creek,  west  slope  of  Big- 
horn Mountains,  Wyo.  (altitude  8,000  feet),  September  11,  1893,  by 
Vernon  Bailey;  male  adult,  skin  and  skull,  no.  56050,  U.  S.  Natl. 
Mus.  (Biological  Survey  collection)  (orig.  no.  4383). 


^  Colorado  Mus.  Nat.  Hist. 
'  E.  R.  Warren  collection. 
''  Univ.  Michigan  Mus.  Zool. 
^  Kansas  Univ.  Mus.  Nat.  Hist. 
•Cleveland  Mus.  Nat.  Hist. 
«Amer.  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  115 

Range. — The  Bighorn  Mountains  and  Bighorn  Basin,  Wyo. ;  south 
to  head  of  Red  Canyon,  near  Miners  Delight,  Fremont  County,  and 
west  to  New  Fork  of  Green  River  (fig,  9).  Reported  also  from 
Franks  Butte,  near  head  of  Sage  Creek,  Park  County,  Wyo.  Zonal 
range:  Transition. 

External  characters — Similar  in  coloration  to  C.  t.  tridecemline- 
atus  but  slightly  paler  and  much  smaller;  size  of  G.  t.  'parvus  but 
much  darker. 

Cranial  characters. — Skull  smaller  than  that  of  tridecemlineatus 
or  C.  t.  pallidus;  similar  to  that  of  parvus  but  relatively  longer,  with 
smaller  audital  bullae  and  much  longer  nasals. 

Color. — Summer  pelage  (September)  :  Dark  dorsal  stripes  mummy 
brown ;  light  spots  and  stripes  grayish  white ;  nose  and  front  of  face 
cinnamon  buff ;  sides  of  face  pinkish  buff,  washed  with  fuscous ;  front 
feet  pinkish  buff;  hind  feet  tilleul  buff,  the  thighs  cinnamon  buff, 
washed  with  snuff  brown;  tail  above,  like  the  back  at  base,  shading 
to  fuscous  black  on  terminal  half,  edged  with  tilleul  buff  or  buffy 
white;  tail  beneath,  cinnamon  or  pinkish  cinnamon,  overlaid  and 
edged  with  buffy  white  and  fuscous  black;  under  parts  and  lower 
sides  soiled  whitish,  washed  with  pinkish  buff. 

Measurements. — Average  of  3  adults  (1  male,  2  females)  from  Bighorn  Moun- 
tains and  Bighorn  Basin:  Total  length,  206.3  (203-211)  ;  tail  vertebrae,  74  (73- 
75)  ;  hind  foot,  31  (30-32).  Skull:  Average  of  3  adults  (1  male,  2  females) 
from  same  localities:  Greatest  length,  36.4  (35.8-36.8)  ;  palatilar  length,  16.4 
(;16.2-16.5)  ;  zygomatic  breadth,  19.9  (19.5-20.1)  ;  cranial  breadth,  16  (16-16.1)  ; 
interorbital  breadth,  7.5  (7.1-7.7)  ;  postorbital  constriction,  11.3  (10.8-11.6)  ; 
length  of  nasals,  13.2  (12-14.5)  ;  maxillary  tooth  row,  6.6  (6.4-6.8). 

Remarks. — The  Bighorn  ground  squirrel  is  an  inhabitant  of  moun- 
tains and  foothills,  and  is  decidedly  darker  than  the  races  living  on 
the  plains.     The  limits  of  its  range  are  not  well  knoAvn. 

Specimens  examined. — Total  number,  6,  as  follows: 

Wyoming:  Bighorn  Basin  (head  of  Kirby  Creek,  Hot  Springs  County),  1;  Big- 
horn Mountains  (west  slope,  near  head  of  Canyon  Creek),  2  ;  Miners  Delight 
(near  head  of  Twin  Creek,  Fremont  County),  1;  New  Fork  of  Green  River 
(Lander  Road),  2. 

CITELLUS  TRIDECEMLINEATUS  HOLLISTERI  Bailet 

Hor.LisTEB's  Striped  Ground  Sqihrrel 

Citellus  tridecemlineatus  hoUisteri  Bailev,  Biol.  Soc.  Wash.  Proc.  26:  131,  May 
21,  1913. 

Type. — Collected  in  Elk  Valley,  Mescalero  Indian  Reservation, 
Sacramento  Mountains,  N.  Mex.  (8,000  feet  altitude),  September  11, 
1902,  by  Vernon  Bailey;  female  adult,  skin  and  skull,  no.  119025, 
U.  S.  Natl.  Mus.  (Biological  Survey  collection)   (orig.  no.  7963). 

Range. — Sacramento  Mountains,  N.  Mex.,  and  mountain  valleys  of 
northeastern  New  Mexico;  western  limits  of  range  not  known  (fig. 
9).     Zonal  range:  Transition. 

External  characters. — Similar  to  C.  t.  alleni,  but  dark  dorsal  stripes 
slightly  more  reddish  and  light  stripes  tinged  with  buff,  the  median 
pair  of  light  stripes  usually  continuous ;  hind  feet  washed  with  buff. 

Cranial  characters. — Skull  similar  to  that  of  alleni.,  but  with 
heavier  and  more  widely  spreading  zygomata;  larger  than  that  of 
C.  t,  parvus. 


116  NORTH  AMERICAN  FAUNA  [No.  56 

Color. — Summer  'pelage  (September)  :  Dark  dorsal  stripes  chest- 
nut brown;  crown  same  color  mottled  with  whitish  spots;  a  broad 
whitish  or  buffy  eye  ring;  front  of  face  tawny  olive;  sides  of  nose 
pinkish  buff;  light  dorsal  stripes  and  spots  grayish  wliite,  faintly 
tinged  with  buff;  front  legs  and  feet  cinnamon  buff;  hind  legs  cin- 
namon; hind  feet  dull  white,  washed  with  buff;  tail  (above  and 
below)  chestnut  brown  at  base,  becoming  black  on  distal  half,  over- 
laid with  tilleul  buff;  under  parts  and  sides  pinkish  buff  or  pale 
cinnamon  buff. 

Measurements. — Average  of  5  adult  females  from  type  locality:  Total  length, 
211.2  (200-232)  ;  tail  vertebrae,  71.8  (60-85)  ;  hind  foot,  30.7  (30-32).  Skull: 
Average  of  4  adult  females:  Greatest  length,  36.1  (35-37.4)  ;  palatUar  length, 
16.7  (16-17)  ;  zygomatic  breadth,  20.7  (19.3-21.7)  ;  cranial  breadth,  15.9  (15.3- 
16.4)  :  interorbital  breadth,  7.3  (6.5-7.8)  ;  postorbital  constriction,  11.6  (11.2- 
12.2)  ;  length  of  nasals,  13.2  (12.8-13.8)  ;  maxiUary  tooth  row,  6  (5.9-6.2). 

Bemarks. — This  race  seems  to  have  a  discontinuous  range;  de- 
scribed from  the  Sacramento  Mountains,  southern  New  Mexico,  it 
proves  to  occupy,  also,  the  mountain  valleys  in  the  northeastern  part 
of  the  State  north  nearly  or  quite  to  the  Colorado  line,  where  it  inter- 
grades  with  0.  t.  arenicola  of  the  plains  region  to  the  eastward.  The 
specimens  from  this  region  have  the  dark  dorsal  stripes  more  brown- 
ish (less  reddish)  than  in  the  typical  series.  Further  collecting  in 
central  New  Mexico  may  result  in  partly  connecting  this  range. 
Although  very  similar  in  external  appearance  to  alleni,,  of  the  Big- 
horn Mountains,  Wyo.,  the  range  of  holUsten  is  separated  from  the 
range  of  that  form  by  a  wide  area  in  western  Colorado  mainly 
occupied  by  parvus. 

Bailey  (1931,  p.  119)  has  referred  the  specimens  from  Moreno 
Valley  to  alleni,  on  the  strength  of  their  close  resemblance  to  that 
race  in  color;  however,  the  skulls  of  these  New  Mexico  specimens 
agree  closely  with  those  of  hollisteri  and  differ  from  those  of  alleni 
in  heavier  build  and  more  widely  spreading  zygomata.  It  seems 
preferable,  therefore,  by  reason  of  their  proximity  to  the  type  region 
of  hollisteH.,  to  refer  them  to  that  race. 

Specimens  exannin£d. — Total  number,  17,  as  follows : 

New  Mexico:  Cimarron  (35  miles  northwest),  1;  Las  Vegas  (12  miles  north), 
1;  Maxwell,  1;"  Mescalero  Reservation  (Elk  VaUey,  Sacramento  Moun- 
tains), 7;  Mora   (10  miles  south),  2;  Moreno  Valley   (Colfax  County),  5. 

CITELLUS   TRIDECEMLINEATUS  MONTIOOLA  HowEiJ. 

Aeizona  Stkiped  Geounb  Squieeel 

Citellus  tridecemlineatus  mcnticola  Howell,  Biol.  Soc.  Wash.  Proc.  41:  214, 
Dec.  18,  1928. 

Type. — Collected  at  Marsh  Lake,  Wliite  Mountains,  Ariz.  (9,000 
feet  altitude),  June  15,  1915,  by  Edward  A.  Goldman;  male  adult, 
skin  and  skull,  no.  209255,  U.  S.  Natl.  Mus.  (Biological  Survey  col- 
lection)  (orig.  no.  22616). 

Range. — Known  only  from  the  type  locality  (fig.  9).  Zonal 
range:  Transition. 

External  characters. — Similar  to  C.  t.  alleni  but  upper  parts 
slightly  and  under  side  of  tail  decidedly  more  reddish.    Similar  to 


"Reading   (Pennsylvania)   Public  Mus, 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  WJ 

C.  t.  parvus^  but  larger ;  coloration  of  upper  parts  and  under  side  of 
tail  darker;  under  parts  more  buffy  (less  whitish).  Compared  with 
G.  t.  hollisteri:  Upper  parts  paler,  the  light  dorsal  stripes  more 
whitish  (less  buffy) ;  under  side  of  tail  more  reddish. 

Cranial  characters. — Skull  similar  to  that  of  hollisteri^  but  nasals 
shorter;  decidedly  larger  than  that  of  2)arvus^  but  with  relatively 
smaller  molars;  similar  to  that  of  alleni  but  with  heavier  and  more 
spreading  zygomata. 

Color. — Summer  pelage  (June  15)  :  Dark  dorsal  stripes  chestnut 
brown;  light  stripes  and  spots,  and  eye  ring,  creamy  white;  front 
feet  pinkish  buff;  hind  feet  cartridge  buff,  the  thighs  pinkish  cin- 
namon or  mikado  brown;  tail  above,  pinkish  cinnamon  on  proximal 
third,  the  remainder  fuscous  black,  broadly  edged  with  cartridge 
buff  (the  basal  portion  of  the  hairs  likewise  cartridge  buff) ;  tail 
beneath,  russet,  bordered  with  fuscous  black  and  tipped  with  car- 
tridge buff;  under  parts  and  lower  sides  cartridge  buff. 

Measuremeiits. — Average  of  7  adults  (4  males,  3  females)  from  type  locality: 
Total  length,  221.7  (214-227)  ;  tail  vertebrae,  78  (70-81)  ;  hind  foot,  30.4 
(29-32).  »S7.w 7?.- Average  of  4  adult  males:  Greatest  length,  37  (37-37.1); 
palatilar  length,  17.3  (17-17.5)  zygomatic  breadth,  21.4  (21.1-21.7)  ;  cranial 
breadth,  16.6  (16.3-17)  ;  interorbital  breadth,  7.8  (7.3-8)  ;  postorbital  constric- 
tion, 11.7  (11.3-12.3)  ;  length  of  nasals,  12.7  (12.5-13)  ;  maxillary  tooth  row, 
5.9  (5.7-6.1).  Average  of  3  adult  females:  Greatest  length,  35.8  (35-36.1); 
palatilar  length,  16  (15.5-16.5)  ;  zygomatic  breadth,  20  (one  specimen)  ; 
cranial  breadth,  15.9  (15.7-16.4)  ;  interorbital  breadth,  7.2  (7.1-7.3)  ;  postorbital 
constriction,  12  (11.7-12.2)  ;  length  of  nasals,  12.3  (11.8-12.8)  ;  maxillary  tooth 
row,  (5.6-6.2). 

Remarks. — This  race  is  similar  to  alleni  of  the  Bighorn  Moun- 
tains, Wyo. ;  it  resembles,  also,  hollisteri  of  eastern  New  Mexico,  but 
is  somewhat  paler  and  differs  in  the  color  of  the  under  side  of  the 
tail.  Typical  specimens  are  known  only  from  the  higher  parts  of 
the  White  Mountains,  Ariz.;  specimens  from  Springerville,  at  the 
base  of  the  mountains  and  from  the  Datil  Mountains,  N.  Mex.,  agree 
with  parvus  in  the  coloration  of  the  tail  and  in  skull  characters,  but 
are  about  as  dark  as  typical  monticola.,  thus  indicating  intergrada- 
tion  between  these  forms. 

Specimens  examined. — Total  number,  7,  from  Marsh  Lake,  Wliite 
Mountains,  Ariz. 

CITELLUS   TRIDECEMLINEATUS   PARVUS    (Allehst) 

Least  Striped  GRor?7D  Sqtjibkel 

Spcrmophilus  trideccmlineatus  parvus  Allen,   Amer.   Mus.  Nat.  Hist.   Bull.  7: 

337,  Nov.  8,  1895. 
[Citellus  tridecimlhieatus]  parvus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  1904. 

Ty/^e.— Collected  at  Kennedy's  Hole,  Uncompahgre  Indian  Reser- 
vation (20  miles  northeast  of  Ouray,  Uintah  County),  Utah,  May  2, 
1895,  by  W.  W.  Granger;  male  adult,  skin  and  skull,  no.  W^,  Amer. 
Mus.  Nat.  Hist.  (ori<2^.  no.  537). 

Range. — Uncompahgre  Plateau,  eastern  Utah  and  desert  regions 
of  southwestern  Wyoming,  northwestern  and  south-central  Colorado, 
and  west-central  New  Mexico ;  north  to  Natrona  County,  AVyo. ;  east 
to  Independent  Kock,  Wyo.,  south  to  St.  Augustine  Plains,  N.  Mex.; 
and  west  to  Springerville,  Ariz.  (fig.  9).  Zonal  range:  Upper 
Sonoran. 


llg  NORTH  AMERICAN  FAUNA  [No.  56 

External  characters. — Similar  to  G.  t.  arenicola  but  much  smaller 
and  slightly  darker ;  median  pair  of  light  dorsal  stripes  more  or  less 
broken  into  spots;  tail  not  reddish  beneath.  Compared  with  G.  t. 
■pallidus:  Size  much  smaller  and  coloration  more  reddish. 

Cranial  characters. — Skull  similar  to  that  of  C.  t.  alleni  but  slightly 
smaller  and  relatively  broader,  with  shorter  nasals  and  larger  audital 
bullae;  decidedly  smaller  than  those  of  arenicola  and  pallidus. 

Color. — Winter  pelage  (type,  May  2)  :  Front  of  face  dull  pinkish 
buff ;  top  of  head  sayal  brown,  mottled  with  grayish  white ;  eye  ring 
buff'y  white;  dark  dorsal  stripes  walnut  brown;  light  stripes  and 
spots  creamy  white;  sides  of  head  and  neck  and  front  feet  washed 
with  pinkish  buff;  hind  feet  dull  whitish;  tail  above  and  below, 
pinkish  cinnamon,  shading  to  fuscous  on  distal  half,  overlaid  with 
grayish  white;  under  parts  white.  Summer  pelage  (Bitter  Creek, 
Wyo.,  August)  :  Dark  dorsal  stripes  snuff  brown ;  tail  heavily  over- 
laid on  both  surfaces  with  cinnamon  buff. 

Measurements. — Average  of  5  adult  males  from  Utah  (the  type  and^  others 
from  Ouray)  :  Total  length,  189  (170-202)  ;  tail  vertebrae,  71  (69-72)  ;  hind  foot, 
28  (27-29),  Average  of  12  adults  from  Bitter  Creek,  Wyo.,  and  Snake  River, 
Colo.:  204.6  (189-228)  ;  tail  vertebrae,  76.7  (65-87)  ;  hind  foot,  32.9  (28-31). 
Skull:  Average  of  4  adult  males  (type  from  Utah ;  2  from  Bitter  Creek,  Wyo.; 
one  from  Snake  River,  Colo.)  ;  Greatest  length,  35.3  (34.6-36.2)  ;  palatilar  length, 
15.5;  zygomatic  breadth,  20.2  (19.7-21);  cranial  breadth,  16.7  (16.4-17.3);  in- 
terorbital  breadth,  7.1  (6.9-7.3)  ;  postorbital  constriction,  11.4  (11.1-11.7)  ; 
length  of  nasals,  11.7  (10.5-12.7)  ;  maxillary  tooth  row,  6.2  (5.9-6.4).  Average 
of  4  adult  females  (Ouray,  Utah,  Bitter  Creek,  Wyo.,  and  Routt  County,  Colo.)  : 
Greatest  length,  33.9  (33.2-34.3)  ;  palatilar  length,  14.9  (14.5-15.5)  ;  zygomatic 
breadth,  19.4  (19.1-19.7)  ;  cranial  breadth,  16.1  (15.8-16.4)  ;  interorbital 
breadth,  7.1  (7-7.2)  ;  postorbital  constriction,  11.2  (11-11.5)  ;  length  of  nasals, 
10.5  (10-11)  ;  maxillary  tooth  row,  6.2  (6-6.4). 

Weight. — One  female  weighed  6  ounces. 

Remarks. — This  subspecies  is  the  smallest  of  the  races  of  G.  tride- 
cemlineatus  and  is  about  as  pale  as  arenicola  from  western  Kansas. 
Its  range  is  imperfectly  known  at  present  and  appears  to  be  discon- 
tinuous. A  good  series  from  Bitter  Creek,  southwestern  Wyoming, 
appears  to  be  typical  and  a  few  specimens  from  northwestern  Colo- 
rado are  also  referred  to  this  race,  although  they  average  darker; 
and  those  from  Lay,  Rangely,  and  Mud  Springs  might  on  the  basis 
of  color  be  referred  to  alleni.  Their  skulls,  however,  are  small,  like 
those  of  parvus.  A  series  from  the  San  Luis  Valley,  southern 
Colorado,  is  provisionally  referred  to  parvus,  although  they  show 
some  color  variations  that  may  necessitate  their  separation  when  it 
is  possible  to  compare  them  with  a  good  series  of  topotypes.  Inter- 
gradation  with  G.  t.  monticola  of  southern  Arizona  is  indicated  by 
small  series  from  Datil  Mountains,  N.  Mex.,  and  Springerville,  Ariz. ; 
with  alleni  by  specimens  from  New  Fork  of  Green  River,  Wyo.,  and 
with  pallidus  by  specimens  from  Casper,  Wyo.  (referred  to  pallidus). 

Specimens  examined. — Total  number,  69,  as  follows: 

Arizona:  Springerville,  4. 

Colorado:  Antonito,  2;  Axial  Basin  (12  miles  southeast  of  Lay),  2;  Escalante 
Hills  (Moffat  County),  1;  Fort  Garland,  3;  Medano  Ranch  (Alamosa 
County),  2;"  Mosca  (Alamosa  County),  1;"  Muddy  Creek  (Huerfano 
County),  1;";  Mud  Springs  (Garfield  County,  30  miles  southeast  of 
Meeker),  4;"  Rangely  (Rio  Blanco  County),  2;  San  Acacio  (Costilla 
County),  3;"  San  Luis  Lakes  (Alamosa  County),  1;"  Snake  River  (Mo(- 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  HQ 

fat  County),  5;""  Two  Bar  Spring  (western  Moffatt  County),  1;"  West- 
cliff  e  (Custer  County),  7. 
New  Mexico:  Datil  Mountains  (12  miles  northwest  of  Datil),  2;  St.  Augustine 

Plains  (near  Monica  Spring),  2. 
Utah:  Fruitland,  3;"  Ouray  (12  miles  southwest),  4;"  Uncompahgre  Indian 

Reservation,  4."  ^^ 
Wyoming:  Big  Sandy  (Sublette  County),  1;  Big  Sandy  Creek  (Lander  Road), 

1;  Bitter  Creek  (Kinney  Ranch,  Sweetwater  County),  9;"  Green  River,  1; 

Independent  Rock  (mouth  of  Dry  Creek,  Natrona  County),  1;  Myersville 

(Fremont  County),  1;  Sun  (Natrona  County),  1. 

CITELLUS  MEXICANUS   (Eexlb35En) 
[Synonymy  under  subspecies] 

Specific  characters. — Size  large;  hind  foot  38-51  mm;  tail  about 
40  percent  of  the  total  length ;  skull  length,  41-52.5  mm.  Skull  sim- 
ilar to  that  of  C.  tridecemlineatus  but  considerably  larger ;  brain  case 
less  elongate,  more  nearly  square ;  zygomata  more  widely  expanded ; 
audital  bullae  large  and  smoothly  rounded.  Ears  broad  and  low, 
rising  3-5  mm  above  crown.  Coloration  of  upper  parts  varying 
from  wood  brown  or  buffy  brown  to  sayal  brown  or  snuff  brown, 
marked  with  squarish  white  spots  arranged  in  linear  rows,  usually 
nine  in  number,  the  spots  sometimes  partly  confluent,  at  other  times 
more  or  less  obsolete;  head  buffy  brown  or  wood  brown,  sprinkled 
with  white,  the  nose  clay  color  or  cinnamon  buff;  feet,  sides,  and 
under  parts  white  to  pinkish  buff;  tail  above,  mixed  fuscous  and 
grayish  or  buffy  white;  tail  beneath,  avellaneous  to  cinnamon  buff, 
more  or  less  obscured  by  grayish  or  buffy  white. 

CITELLUS  MEXICANUS  MEXICANUS    (Erxleben) 

Mesican  Ground  Squirkex 

(Pis.  25,  C;  30,  C) 

[8ciuru8'\  mexicanus  Erxleben,  Syst.  Regni  Anim.  1 :  428, 1777. 

Citillus  mexicanus  Lichtensteiu,  Darstel.   Saugt.,  plate  31   (and  accompanying 

text),  1827-1834. 
Spermophilus  mexicanus  Wagner,  Schreber's  Siiugt.,  Sup.,  3:  250,  1843. 
Otospermophilus  mexicanus  Brandt,  CI.  Phys.-Math.  Acad.  Sci.  St.  Petersbourg 

Bull.  2 :  379,  1844. 
Citellus  mexicanus  Merriam,  Biol.  Soc.  Wash.  Proc.  16 :  80, 1903. 

Type. — None  designated ;  type  locality  fixed  at  Toluca,  Mexico,  bv 
Mearns  (1896,  p.  443). 

Range. — Central  Mexico,  from  northern  Jalisco  and  Guanajuato 
south  to  southern  Puebla  (fig.  10).     Zoiuil  range:  Lower  Sonoran. 

External  characters. — Size  large;  hind  foot,  46.5-51  mm;  skull 
length,  45.3-52.5;  coloration  averaging  darker,  with  more  buffy 
sides  and  under  parts  than  in  C.  m.  parvidens. 

Cranial  characters. — Skull  similar  to.  that  of  G.  tHdecemlineatus 
tridecemlineatus  but  much  larger;  brain  case  relatively  broader; 
audital  bullae  larger  and  more  inflated. 

Color. — Upper  parts  buffy  brown,  sayal  brown,  or  snuff  brown, 
the  dorsum  covered  with  numerous  squarish  white  spots  arranged  in 
nine  linear  rows  (sometimes  with  indications  of  another  pair  of  lines 

^  E.  R.  Warron  collection. 
«  Colo.  Mus.  Nat.  Hist. 
"  Amer.  Mus.  Nat.  Hist, 
i"^  Field  Mus.  Nat.  Hist. 
"  Carnegie  Mus. 


120 


NORTH  AMERICAN  FAUNA 


[No.  56 


on  lower  sides),  the  middle  row  usually  somewhat  narrower  than 
the  others;  the  lines  sometimes  irregular  and  broken  in  middle  of 
back,  and  spots  sometimes  confluent  on  some  of  the  rows ;  head  buff y 
brown,  with  whitish  tips  to  some  of  the  hairs;  nose  and  front  of 
face  cinnamon  buff  or  clay  color;  eye  ring  white;  feet  pinkish  buff 
or  cartridge  buff;  tail  above,  mixed  fuscous  and  buffy  white,  with 

some  of  the  body  color 
near  the  base ;  tail  be- 
neath, avellaneous  to 
cinnamon  buff,  bor- 
dered with  fuscous 
and  edged  with  buffy 
white. 

Measurements. — ^Aver- 
age of  10  adults  and  sub- 
adults  from  central  Mex- 
ico (states  of  Hidalgo, 
Queretaro,  Guanajuato, 
and  Mexico):  Total 
length,  349.6  (322-380)  ; 
tail  vertebrae,  144.6  (124r- 
166)  ;  hind  foot,  48.4 
(46.5-51).  Skull:  Aver- 
age of  13  adults  (6  males, 
7  females)  from  Quere- 
taro, Guanajuato,  and  Ja- 
lisco :  Greatest  length,  49 
(45.3-52.5)  ;  palatilar 
length,  23.5  (22-24.2)  ; 
zygomatic  breadth,  28.9 
(27-30.3);  cranial 
breadth,  20.4  (19.3-21.1)  ; 
interorbital  breadth,  10.4 
(9.6-11.1)  ;  postorbital 
constriction,  14  (13.2- 
14.8)  ;  length  of  nasals, 
17.8  (15.8-20.1);  maxillary 
tooth  row,  9.8  (9.3-10.5). 

Remarks.  —  This 
strikingly  marked 
ground  squirrel  was 
one  of  the  first  North 
American  species  to 
be  recognized,  having 
been  named  by  Erxle- 

FiGOKE  10. — Distribution  of  the  subspecies  of  Citellus  mexi-   l-\pn  in  1777     Tt  tq  pnm- 
canus;  1,  V.  m.  parvidens;  2,  C.  m.  mexicanus.  '    *    T   ,  ?  ^      \ 

mon  on  the  tableland 
of  central  Mexico,  occupying  an  area  lying  mainly  south  of  the  range 
of  0.  spilosoma.  It  resembles  this  species  only  slightly,  being  much 
larger  and  more  heavily  spotted.  It  varies  considerably  in  color; 
the  extremes  of  coloration  might  be  designated  as  a  brovvn  phase 
and  a  drab  or  olivaceous  phase,  but  there  are  several  intermediate 
shades  in  any  large  series  of  specimens. 

Specimens  examined. — Total  number,  31,  as  follows: 

Guanajuato :  Celaya,  1 ;  Silao,  3 ;  Irolo,  1 ;  Marques,  1. 

Jalisco:  Atemajac,  7;  Lagos,  2;  Zapotlan,  6. 

Mexico:  Tlalpam  (Federal  District),  4. 

Puebla:  Atlixco,  1 ;  San  Andres  Chalchicomula,  1 ;  San  Martin,  1. 

Queretaro:  Tequisquiapan,  2. 

Tlaxcala:  Huamantla,  1. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  121 

CITELLUS  MEXICANUS  PARVIDENS   (Meaens) 
Rio  Grande  Ground  Sqxjibbei, 

Spermophilus  mexicanus   parvidens  Mearns,   U.    S.   Natl.   Mus.  Proc.   18:  443, 

May  23,  1896  (advance  sheets  issued,  Mar.  25,  1896). 
[Citelliis  mexicanus^  parvidens  Elliot,  Field  Columb.  Mus.,  Zool.  Ser.  4:  146, 

1904. 

Type. — Collected  at  Fort  Clark,  Kinney  County,  Tex.,  March  21, 
1893,  by  E.  A.  Mearns;  male  adult,  skin  and  skull,  no.  63073,  U.  S. 
Natl.  Mus.  (orig.  no.  2312). 

Range. — Northeastern  Mexico,  ^Yestern  Texas,  and  southeastern 
New  Mexico ;  north  to  Eoswell,  N,  Mex.  and  Borden  County,  Tex. ; 
east  to  Austin  and  Rockport,  Tex.;  south  to  southern  Tamaulipas; 
west  to  central  Coahuila  and  extreme  western  Texas  (El  Paso)  (fig. 
10).    Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  C.  m.  mexicanus  but  decidedly 
smaller;  coloration  averaging  paler,  with  less  buff  on  under  parts 
and  hind  legs. 

Cranial  characters. — Skull  similar  to  that  of  mexicanus  but 
decidedly  smaller. 

Color. — Upper  parts  varying  from  wood  brown  to  sayal  brown  or 
snuff  brown,  with  nine  usually  distinct  linear  rows  of  large  white 
spots;  head  same  color  as  back,  flecked  with  white;  nose  patcli  cin- 
namon buff;  eye  ring  white ;  sides  of  face  and  neck  smoke  gray;  sides 
of  body  and  under  parts  creamy  white  or  cartridge  buff;  hind  legs 
cinnamon  buff  to  cartridge  buff;  feet  pinliish  buff  or  buffy  white; 
tail  above,  mixed  fuscous  and  buffy  white;  tail  beneath,  cartridge 
buff  or  pinkish  buff,  more  or  less  overlaid  with  buffy  white. 

Measurements. — Average  of  12  ndults  from  type  locality:  Total  length,  300.S 
(280-313);  tail  vertebrae,  118.3  (110-126);  hind  foot,  40.9  (38-43).  Skull: 
Average  of  17  adults  (9  males,  8  females)  from  type  locality:  Greatest  length, 
43  (41.1-44.8)  ;  palatilar  length,  20.7  (10.5-22)  ;  zygomatic  breadth,  25.3 
(23.5-27.1)  ;  cranial  breadth,  18.6  (17.S-19.5)  ;  interorbital  breadth,  9.4  (8.2- 
10.5)  ;  postorbital  constriction,  12.7  (12-14.6)  ;  length  of  nasals,  15.1  (13.5- 
16.2)  ;  maxillary  tooth  row,  8  (7.3-8.9). 

Remarhs. — This  northern  race  of  mexicanus  is  distinctly  larger 
than  the  typical  race,  and,  like  it,  shows  a  great  amount  of  variation 
in  color;  the  majority  of  specimens  of  parvidens  are  paler  than  mex- 
icanus but  some  in  the  brown  phase  are  not  appreciably  different  in 
color. 

Although  actual  integradation  with  mexicanus  is  not  shown  by 
the  material  in  hand,  it  seems  highly  probable  that  additional  col- 
lecting in  Mexico,  particularly  in  &an  Luis  Potosi,  will  result  in  the 
discovery  of  intergrades. 

Specimens  examined. — Total  number,  225,  as  follows: 

Coahuila:  Las  Vacas,  1;  Monclova,  1;  Sabinas,  1;  Saltillo,  8. 

New  Mexico:  Carlsbad,  2;  Roswell,  3. 

Nuevo  Leon:  Montemorelos,  1;  Pesqueria  Grande  (probably  near  Monterey),  1; 

Santa  Catarina,  1. 
Tamaulipas:  Bagdad,  3;  Camargo,  2;  Mier,  5;  Nuevo  Laredo,  1;  Reynosa,  1; 

Victoria,  1. 
Texas:    Adams    (Pecos   County),   2;    Alice,   1;    Alpine,    1;    Altuda    (Brewster 

County),  7 ;  Beeviile,  1 ;  Big  Spring,  2 ;  Brownsville,  20  ;  Cameron  County,  7  ; 

Carrizo  Springs,  2 ;  Colorado,  4 ;  Comstock,  3 ;  Concho  County,  1 ;  Corpus 

Christi,  9;"  Cotulla,  3;  Del  Rio,  3;  Devils  River   (at  mouth),  2;   Eagle 


"  Three  in  Field  Mus.  Nat.  Hist. 


122  NORTH  AMERICAN  FAUNA  [No.  56 

Pass,  3;  East  Painted  Cave  (near  moutli  of  Pecos  River),  1;  Fort  Clark 
(Kinney  County),  33;  Fort  Lancaster  (Crockett  County),  6;  Fort  Stockton 
(25  miles  west),  2;  Juno  (Val  Verde  County),  1;  La  Hacienda  (10  miles 
southeast  of  Hidalgo),  1;  Langtry  (Val  Verde  County),  15;  Laredo,  5; 
Lomita  Ranch  (Hidalgo  County),  2;  Lozier  (Terrell  County),  1;  Marathon, 
1;  Mason,  1;  Monahans  (Ward  County),  4;  Norias  (Kenedy  County),  2;  ^*° 
Pecos,  4;  Port  Isabel,  14:^^  Rio  Grande  City,  5;  Rock  Springs  (10  miles 
west),  1;  Rockport,  1;"  Samuels  (Val  Verde  County),  4;  San  Angelo  1; 
San  Diego,  5;  Sarita  (Kenedy  County),  3;""  Sheffield  (Pecos  County),  3; 
Stanton,  3;  Sycamore  Creek  (Val  Verde  County),  3. 

CITELLUS  SPILOSOMA  GROUP 

CITELLUS  SPILOSOMA  (BENNETtT) 

[Synonymy  under  subspecies] 

Specific  characters. — Size  small  to  medium;  hind  foot,  28-38  mm; 
tail,  55-88 ;  skull  length,  34.1-42.7.  Skull  similar  to  that  of  C.  tri- 
decemlineatus.,  but  relatively  shorter  and  broader,  especially  the 
rostrum  and  interorbital  region ;  audital  bullae  much  larger. 

Color. — Upper  parts  drab,  cinnamon  drab,  avellaneous,  smoke  gray, 
fawn,  wood  brown,  snuff  brown,  or  verona  brown,  more  or  less  spotted 
with  squarish  white  spots;  tail  above,  usually  similar  to  the  back, 
darkened  at  the  tip  with  fuscous  black;  tail  beneath,  pinkish  buff, 
pinkish  cinnamon,  vinaceous  cinnamon,  or  cinnamon  buff. 

CITELLUS  SPILOSOMA  SPILOSOMA  (Bennett) 

Bennett's  Spottbh)  Ground  Sqtjirebl 

(Pis.  25,  A;  30,  A) 

Spermophiliis  spilosoma  Bennett,  Zool.  Soc.  London  Proc.  1833 :  40. 
Citellus  spilosoma  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  20 :  209,  1904. 

Lectotype  (Thomas,  1927,  p.  548).— No.  53.8.29.5,  British  Museum; 
male,  skin  (without  skull),  from  an  unknown  locality;  in  the  absence 
of  any  definite  information  relative  to  the  type,  the  type  locality  is 
hereby  fixed  at  Durango,  Durango.^^ 

Range. — Central  Mexico,  from  Durango  City  south  to  Aguas- 
calientes;  east  to  San  Luis  Potosi  (city)  (fig.  11).  Zonal  range: 
Lower  Sonoran. 

External  characters. — Size  large ;  tail  long,  with  considerable  black 
at  distal  end;  dorsal  spotting  rather  fine,  becoming  obsolete  on  the 
anterior  part  of  the  body. 

Cranial  characters. — Skull  similar  in  shape  to  that  of  C.  mexicanus 
mexicanus  but  much  smaller;  similar  to  that  of  C.  tridecemlineatus 
texensis  but  with  broader  brain  case  and  larger  audital  bullae. 

Color. —  (Jesus  Maria,  San  Luis  Potosi,  Sept.  10)  :  Upper  parts 
fawn  color,  moderately  speckled,  chiefly  on  hinder  back,  with  small 
squarish  spots  of  white;  eye  ring  buffy  white;  sides  of  faca  neck, 
and  shoulders  washed  with  smoke  gray ;  front  feet  pinkish  buff ;  hind 
feet  cartridge  buff  •  tail  above,  vinaceous  fawn,  the  hairs  on  the  distal 
half  with  a  broad  subterminal  band  of  black,  tipped  with  buffy 
white;  tail  beneath,  vinaceous  cinnamon,  more  or  less  obscured  by 
black  and  edged  with  buffy  white;  under  parts  white,  tinged  with 
pale  buff. 


« Field  Mus.  Nat.  Hist. 
isaAcad.  Nat.  Sci.  Philadelphia, 
"See  remarks,  p.  123. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


123 


A  specimen  from  Durango,  Durango,  June  27  (said  to  agree  closely 
with  the  type)  is  slightly  more  reddish  above  than  this  description, 
the  general  tone  about  vinaceous  fawn. 

Measurements. — Average  of  11  adults  from  Aguascalientes  and  San  Luis 
Potosi  (Jesus  Maria  and  Hacienda  La  Parada)  :  Total  length,  238.4  (230-250)  ; 
tail  vertebrae,  77.7  (71-88);  hind  foot,  35.8  (34-37).  Skull:  Average  of  11 
adults   (2  males,  9  females)    from   San  Luis  Potosi  and  Zacatecas :  Greatest 

length,    40.9    (39.3-42.7)  ; 

1^ J  J  \  n    palatilar   length,   1S.8 

'■^•"-ll,  i  "C  K""^  (18.2-19.8)  ;    zygomatic 

.  ^  >.      1    breadth    24.5     (23-26.6)  ; 

cranial  breadth,  18.6 
(17.8-20)  ;  interorbital 
breadth,  8.8  (8-10)  ;  post- 
orbital  constriction,  14.2 
(13.1-15.9)  ;  length  of  na- 
sals, 14.2  (13.7-15.2)  ; 
maxillary  tooth  row,  7.6 
(7-8). 

Re^narJcs. — Origi- 
nally described  in  1833 
from  an  unknown  lo- 
cality, this  species  has 
never  been  fully  char- 
acterized and  it  seems 
impossible  to  discover 
the  exact  source  of  the 
type  specimens.  They 
were  stated  by  the  de- 
scriber  to  have  been 
obtained  in  "that  part 
of  California  which 
adjoins  to  Mexico." 
Baird  (1857,  p.  322) 
states:  "this  species 
was  first  described 
from  specimens  col- 
lected on  the  western 
coast  of  Mexico",  but 
does  not  give  the 
source  of  his  informa- 
tion. However,  since 
the  species  is  not 
known  to  occur  to  the 
westward  of  the  Si- 
erra Madre  in  Mexico,  this  statement  cannot  be  taken  literally. 

At  the  time  the  species  was  described  (1833),  few  expeditions  had 
been  made  to  the  region  where  it  lives.  Capt.  Beechey's  expedition, 
however,  remained  at  San  Bias,  on  the  coast  of  Tepic,  from  December 
8,  1827,  to  February  (?),  1828,  and  Mr.  Lay,  the  naturalist  of  the 
expedition,  "visited  and  remained  for  a  long  time  at  Tepic,  54  miles 
from  San  Bias,  inland"  (Hooker  and  Arnott,  1841,  p.  1),  and  it  seems 
not  at  all  improbable  that  the  type  specimens  may  have  been  obtained 
by  this  expedition. 

In  order  to  settle,  if  possible,  the  identity  of  typical  spilosoma, 
several  specimens  of  this  species  from  central  Mexico  and  several  from 


Figure  11. — Distribution  of  Citellus  perotcnsis  and  of  the 
subspecies  of  C.  spUosoma:  1,  O.  s.  obsoletus ;  2,  C.  8. 
pratensis;  3,  C.  s.  cruptospllotus ;  4,  C.  a.  major;  5,  G.  s. 
canescens;  6,  C.  s.  annectens ;  7,  C.  s.  pallescens ;  8,  0.  8. 
spiloaovia;  9,  C.  perotensis. 


124  NORTH  AMERICAN  FAUNA  [No.  56 

southern  Arizona  {C.  s.  canescens)  Avere  forwarded  to  the  late  Old- 
field  Thomas,  at  the  British  Museum,  who  kindly  compared  them  with 
the  cotypes  in  that  institution.    He  wrote  as  follows : 

After  a  careful  comparison  it  appears  to  me  that  the  large  form  from 
TDurango],  central  Mexico  (No.  9459S,  U.  S.  N.  M.)  most  nearly  agrees  with  the 
type  of  spilosoma,  though  unfortunately  the  latter  has  no  skull  to  give  an  abso- 
lute indication  of  size ;  the  feet,  however,  would  appear  to  be  quite  as  large  as 
in  your  specimen.  The  only  difference  is  that  our  specimens  are  of  a  rather 
stronger  cinnamon  colour  anteriorly,  especially  on  the  crown,   less  greyish. 

This  decision  will  involve  no  shifting  of  names,  since  the  other  de- 
scribed forms  in  the  group  are  all  recognizably  different  from  this 
race. 

Specimens  examined. — Total  number,  39,  as  follows: 

Aguascalientes :  Chicalote,  14. 
Durango:  Durango,  13. 
San  Luis  Potosi:  Jesus  Maria,  2. 
Zacatecas:  Berriozabal,  10. 

CITELLUS  SPILOSOMA  PALLESCENS  Howell 

P^u.LiD  Spottjcd  Geound  Squireel 

Citellus  spilosoma  pallescens  Howell,  Biol.  Soc.  Wash.  Proc.  41 :  212,  Dec.  18, 1928. 

Type. — Collected  at  La  Ventura,  Coahuila,  August  10,  1896,  by 
E.  W.  Nelson  and  E.  A.  Goldman;  male  adult,  skin  and  skull,  no. 
79535,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig.  no. 
10016). 

Range. — North-central  Mexico  from  southern  Chihuahua  (Santa 
Rosalia)  southward  to  San  Luis  Potosi  and  eastward  to  southern 
Nuevo  Leon  (Doctor  Arroyo)  (fig.  11) .    Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  G.  s.  spilosoma.,  but  paler.  Com- 
pared with  G.  s.  canescens :  Size  larger ;  tail  longer,  with  more  black 
on  distal  half ;  dorsal  spotting  finer. 

Granial  characters. — Skull  similar  to  that  of  spilosoma  but  aver- 
aging smaller,  with  shorter,  broader  rostrum  and  nasals ;  larger  than 
that  of  G.  s.  canescens,  with  longer,  narrower  rostrum. 

Golor. — (August  specimens,  topotypes)  :  Upper  parts  wood  brown 
or  drab,  finely  speckled,  chiefly  on  hinder  back,  with  white ;  tail  above, 
light  pinkish  cinnamon  on  proximal  half,  the  distal  half  bordered 
with  fuscous  black  and  edged  with  buffy  white ;  tail  beneath,  pinkish 
buff,  bordered  with  fuscous  black  and  buffy  white;  otherwise  as  in 
spilosoma. 

Measurements. — Average  of  12  adults  from  La  Ventura  and  Carneros,  Coa- 
huila: Total  length,  242.6  (232-253);  tail  vertebrae,  84.8  (76-92);  hind  foot, 
35.7  (34.5-37).  Skttll:  Average  of  10  adults  from  La  Ventura:  Greatest  length, 
40.1  (38.9-41.1)  ;  palatilar  length,  17.9  (17.2-18.5)  :  zygomatic  breadth,  23.8 
(22.9-24.5)  ;  cranial  breadth,  18.6  (18.2-19)  ;  interorbital  breadth,  8.4  (7.8-8.9)  ; 
postorbital  constriction,  14  (12.8-15.1;  length  of  nasals,  18.6  (13-14.5)  ;  maxil- 
lary tooth  row,  7.5  (7.1-8.1). 

Bemarks. — This  pale  race,  occupying  the  plains  of  north-central 
Mexico,  is  most  nearly  related  to  spilosoma.  It  intergrades  with  both 
spilosoma  and  canescens.  A  large  series  from  Santa  Eosalia,  Chihua- 
hua, is  nearest  to  pallescens.,  but  shows  approach  to  canescens  in  the 
coarser  spotting  of  some  individuals  and  in  the  size  and  shape  of 
some  of  the  skulls. 


19381  REVISION  OF  THE  GROUND  SQUIRRELS  125 

Specimens  examined. — Total  number,  75,  as  follows : 

Chihuahua:  Escalon,  4;  Santa  Rosalia,  20. 

Coahuila:  Carneros,  6;  Jaral,  l;""  La  Ventura,  17;  Torreon,  6. 

Nuevo  Leon :  Doctor  Arroyo,  2. 

San  Luis  Potosi:  Hacienda  La  Parada  (about  20  miles  northwest  of  San  Luis 

Potosi),  17;  San  Luis  Potosi,  1. 
Zacatecas:  Caiiitas,  1. 

CITELLUS    SPILOSOMA  CANESCENS    (Mebbiam) 

Apache  Spotted  Geoxjnd  Sqttieeel 

(PI.   5) 

Spermophilus  canescens  Merriam,  North  Amer.  Fauna  4 :  38,  Oct.  8,  1S90. 
Spermophilus  spilosoma  macros irilot us  Merriam,  Ibid.,  p.  38,    (Oracle,  Ariz.). 
Anisonyx   (.Xerospermophilns)   canescens  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  7: 

239,  1895. 
Anisonyx  {Xero spermophilus)   spilosoma  macrospilotus  Allen,  loc.  cit.,  p.  239, 

1895. 
[Spermophilus  spilosoma]  microspilotus  Elliot,  Field  Columb.  Mus.  Pub.  Zool. 

Ser.  2:  96,  1901  (accidental  renaming  of  macrospilotus). 
Spermophilus  spilosoma  arens  Bailey,  Biol.  Soc.  Wash.  Proc.  15 :  118,  1902  (El 

Paso,  Tex.).     . 
Citellus  spilosoma  microspilotus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  4 : 

144,  145,  1904. 
Citellus  spilosoma  macrospilotus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6: 

99,  1905. 
Citellus  spilosoma  canescens  Bailey,  North  Amer.  Fauna  53 :  109,  1931. 

Type. — Collected  at  Will  cox,  Cochise  County,  Ariz.,  November  16, 
1889,  by  Vernon  Bailey;  male  juv,,  skin  and  skull,  no.  ^-||^^,  U.  S. 
Natl.  Mus.  (Biological  Survey  collection)   (orig.  no.  676). 

Range. — Southeastern  Arizona  and  southwestern  New  Mexico; 
south  to  Chihuahua  City,  Chihuahua,  Mexico ;  west  to  Altar  Valley, 
Ariz.;  north  to  Gila  Valley  (Pima),  Ariz.;  east  to  Deming,  N.  Mex. 
and  Fort  Hancock,  Tex.  (fig.  11).    Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  G .  s.  pallescens,  but  smaller,  with 
shorter  tail  and  hind  feet;  dorsal  spots  larger,  and  more  numerous 
on  f oreback ;  tail  with  more  black  on  distal  portion. 

Cranial  characters. — Skull  similar  to  that  of  pallescens,  but  smaller, 
with  shorter,  broader  rostrum. 

Color. — Cinnamon  phase  (January)  :  Upper  parts  fawn  color, 
thickly  spotted  over  most  of  the  back  with  rather  large,  quadrangular 
whitish  spots,  more  or  less  obscured  or  obsolete  on  the  f oreback;  a 
broad  white  ring  surrounds  the  eye ;  sides  of  nose  whitish ;  sides  of 
body  washed  with  pinkish  buff;  front  feet  cartridge  buff:  hind  feet, 
white;  tail  above,  vinaceous  fawn,  edged  with  pinkish  buff,  the  hairs 
on  distal  half  with  a  subterminal  band  of  fuscous  black;  tail  beneath, 
cinnamon  buff  with  a  narrow  band  of  fuscous  black  near  the  tip; 
under  parts  white.  Worn  specimens  in  spring  (April  and  May) 
have  the  tail  considerably  darker — dull  orange  cinnamon.  D7'ab  phase 
(May)  :  Upper  parts  light  drab  or  light  cinnamon  drab,  spotted  as  in 
the  cinnamon  phase ;  sides  whitish  or  with  a  very  faint  wash  of  pale 
ivory  yellow. 

Measurements. — Average  of  11  adults  from  Willcox,  Ariz.:  Total  length, 
228.5  (210-247)  ;  tail  vertebrae,  73.8  (07-86)  ;  hind  foot,  32.1  (30-34).  Skull: 
Average  of  10  adults    (4  males,  6  females)   from  Willcox  and  Oracle,  Ariz. ; 


» Field  Mus.  Nat.  Hist. 


126  NORTH  AMERICAN  FAUNA  [No.  56 

Greatest  length,  38.1    (37.5-38.7)  ;  palatilar  length,   17   (16.a-17.5)  ;  zygomatic 
breadth,  23.2  (23-23.9)  ;  cranial  breadth,  18.1  (17.6-19.2)  ;  interorbital  breadth, 
8.3    (7.5-8.9)  ;   postorbital  constriction,   13.8    (13-14.4)  ;   length  of  nasals,   12.8 
(11.6-13.5)  ;  maxillary  tooth  row,  7.2  (6.5-7.4). 
Weight. — Two  specimens  weighed  respectively,  81.5  and  93.4  g. 

Remarks. — The  Apache  ground  squirrel  is  j-eadily  distinguished 
from  the  central  Mexican  forms  {(J.  s.  spilosoma  and  pallescens) 
by  the  larger  and  more  numerous  dorsal  spots.  Specimens  from 
Chihuahua  City  are  typical,  but  south  of  that  point  intergradation 
with  pallescens  occurs.  Specimens  from  El  Paso  and  Fort  Han- 
cock, Tex.,  are  intermediate  between  canescens  and  C.  s.  major.  The 
range  of  this  form  northward  in  Ai'izona  apparently  is  limited  by 
the  Mogollon  Plateau. 
Specimens  examined. — Total  number,  125,  as  follows : 

Arizona:  Buenos  Ayres,  Altar  Valley,  1;  Chiricahua  Mountains  (2  miles  south- 
east of  Moore's  Ranch),  1;^^  Fort  Bowie  (Cochise  County),  1;  Fort  Grant 
(Graham  County),  1;  Fort  Huachuca,  9;  Huachuca  Mountains,  3;^"  La 
Noria,  Santa  Cruz  River,  1 ;  Mowry,  Patagonia  Mountains,  2 ;  Oracle  (Pinal 
County),  6;  Pima,  1;  Tombstone,  2;  Tucson  (24  miles  southeast),  1; 
Willcox,  24. 

Chihuahua :  Casas  Grande,  4 ;  Chihuahua,  15 ;  Lake  Palomas,  1 ;  White  Water, 
Mexican  boundary  line,  1. 

New  Mexico:  Apache  (Grant  County),  1 ;  Deer  Creek  (Hidalgo  County),  2;  Dem- 
ing,  2;  Dog  Spring  (Grant  County),  7;  Fayvrood  (Grant  County),  1; 
Hachita,  3;  Mangos  Valley  (Grant  County),  1;  Monument  15,  Mexican 
boundary  line,  4;  Monument  40,  Mexican  boundary  line,  2;  SUver  City, 
2 ;  Warren,  6 ; ""  Whitmire  Pass,  Playas  Valley,  1. 

Texas:  El  Paso,  10;  Fort  Hancock  (El  Paso  County),  9. 

CITELLUS  SPILOSOMA  MAJOR    (Merkiam) 

New  Mexico  Spotted  Geotjnd  Squierel 

SpermopMlus  spilosoma  major  Merriam,  North  Amer.  Fauna  4 :  39,  Oct.  8,  1890. 
Spermophilns  spilosoma  marginatus  Bailey,   Biol.    Soc.   Wash.   Proc.  15:  118, 

1902  (Alpine,  Tex.). 
[Citellus  stnlosoma]  major  Trouessart,  Cat.  Slamm.,  Sup.,  p.  340,  1904. 

Type. — Collected  at  Albuquerque,  N.  Mex.,  July  22,  1889,  by  Ver- 
non Bailey;  female  adult,  skin  and  skull;  no.  Hm,  U.  S.  Natl. 
Mus.  (Biological  Survey  collection)   (orig.  no.  225). 

Range. — Eastern  New  Mexico,  western  Texas,  western  Oklahoma, 
south Avestern  Kansas  and  southeastern  Colorado;  north  to  Adams 
and  Yuma  Counties,  Colo. ;  east  to  Kinsley,  Kans.,  Woodward,  Okla., 
and  Colorado,  Tex. ;  south  to  Presidio  and  Brewster  Counties,  Tex. ; 
west  to  St.  Augustine  Plains,  N.  Mex.  (fig.  11.)  Zonal  range:  Upper 
Sonoran. 

External  characters. — Similar  to  G.  s.  canescens.^  but  hind  feet 
larger;  dorsal  spots  fewer  and  less  distinct. 

Cranial  characters. — Skull  similar  to  that  of  canescens.,  but  larger, 
with  decidedly  longer  nasals. 

Color. — Upper  parts  varying  from  light  cinnamon-drab  or  avella- 
neous  to  fawn  color  or  mikado  brown  (in  worn  specimens),  spar- 
ingly spotted  on  the  back  with  m.ore  or  less  indistinct  white  spots; 
front  feet  pinkish  buff;  hind  feet  buffy  white;  tail  above,  usually 
same  color  as  the  back,  the  hairs  on  distal  portion  with  a  subterminal 


SI  Acad.  Nat.  Sci.  Philadelphia. 
2ia  Carnegie  Mus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  127 

band  of  fuscous;  tail  beneath,  light  pinkish  cinnamon,  pinkish  buff, 
or  light  vinaceous  cinnamon;  under  parts  and  sides  white,  some- 
times washed  with  cartridge  buff. 

Measriremcnts. — Average  of  8  adults  (3  males,  5  females)  from  Albuquerque 
and  Isleta,  N.  Mex. :  Total  length,  231.7  (221-245)  ;  tail  vertebrae,  76.7  (69-80)  ; 
hind  foot,  35.2  (34-36).  Skull:  Average  of  10  adult  males  from  New  Mexico 
(Albuquerque,  Espaiiola,  Capitan  Mouutains)  and  southern  Colorado  (La 
Junta,  and  Las  Animas  County)  :  Greatest  length,  40.9  (39.7-42.5)  ;  palatilar 
length,  18.6  (18-19.5)  ;  zygomatic  breadth,  24.3  (23.5-25.6)  ;  cranial  breadth, 
18.9  (17.9-19.9)  ;  interorbital  breadth,  8.6  (8.1-9.1)  ;  postorbital  constriction, 
13.7  (12.6-14.8)  ;  length  of  nasals,  14.4  (13.5-15.5)  ;  maxillary  tooth  row,  7.6 
(7-8).  Average  of  10  adult  females  from  New  Mexico  (Albuquerque,  Espaiiola, 
Isleta,  Carrizozo,  Capitan  Mountains)  ;  Greatest  length,  40.4  (39-41.5)  ; 
palatilar  length,  18.2  (17.5-18.8)  ;  zygomatic  breadth,  24.1  (23.4-24.9)  ;  cranial 
breadth,  18.7  (18.1-19.6)  ;  interorbital  breadth,  8.5  (7.8-9.1)  ;  postorbital  con- 
striction, 14  (13.4-14.5)  ;  length  of  nasals,  14.3  (13.2-15.2)  ;  maxillary  tooth 
row,  7.5  (6.2-8). 

Remarks. — This  wide-ranging  form  is  distinguished  from  its  near- 
est neighbors  chiefly  by  its  large  size.  The  drab  phase  is  compara- 
tively rare  and  does  not  appear  in  pure  form — ^that  is,  many  of  the 
specimens  are  more  or  less  intermediate  between  a  drab  and  a  cin- 
namon phase.  Two  specimens  from  8  miles  east  of  Deming,  N.  Mex., 
are  typical  majo?",  while  several  others  from  Deming  are  best  re- 
ferred to  canescens. 

The  present  form  passes  insensibly  into  subspecies  C.  s.  obsoletus; 
most  of  the  specimens  from  eastern  Colorado,  north  of  the  Arkansas 
Valley,  are  so  completely  intermediate  between  the  two  forms  that 
it  is  very  difficult  to  say  which  form  they  most  resemble.  The  series 
from  Las  Animas,  Colo.,  is  clearly  referable  to  major.,  the  skulls 
being  even  larger  than  skulls  of  topotypes  from  New  Mexico.  Speci- 
mens from  Tuttle,  Wray,  and  Barr  Lake  show  approach  to  obsoletus. 

The  series  from  Alpine,  Tex.,  on  which  was  based  the  subspecies 
'"''marginaius''''  of  Bailey,  averages  slightly  darker  than  typical  major^ 
all  of  them  being  in  the  cinnamon  phase,  but  some  specimens  of  the 
tAvo  series  are  indistinguishable;  no  difference  is  apparent  in  the 
amount  of  black  flecking  on  the  back,  which  in  both  forms  is  very 
inconspicuous. 

Specimen.'^  examined. — Total  number,  172,  as  follows: 

Colorado:  Akron,  1;'*  Barr  Lake  (Adams  County),  1;^  Carrizo  Creek  (Baca 
County),  1;"  Elbert  County  (between  Mattison  and  Resolis),  1;"  Foss- 
ton  (Weld  County),  2;**  Hugo,  1;  La  Junta  (18  miles  south),  2;  Lamar, 
3;""  Las  Animas,  9;  Monon  (Baca  County),  2;^  Regnier  (Baca 
County),  1.'' 

Kansas :  Morton  County,  1 ;  *^  Kinsley,  1. 

New  Mexico:  Alamogordo,  5;  Albuquerque,  11;  Bear  Spring  Mountains  (north 
of  Magdalena,  Socorro  County),  4;  Cabra  Springs  (San  Miguel  County),  1; 
Capitan  Mountains  (northwest  foothills),  6;  Carlsbad  ("Eddy"),  7;  Car- 
rizozo, 1;  Deming  (8  miles  east),  2;  Espauola,  7;  Fort  Sumner  (8  miles 
north),  1;  Isleta,  4;  Lake  Valley  (Sierra  County),  1;  Magdalena  (10-15 
miles  southeast),  2;  Maxwell.  1;'*  Mesilla,  3;*°"  Ojo  Caliento  (northeast 
of  Chloride,  Sierra  County),  1;  Rio  Alamosa  (15  miles  north  of  0.jo  Cali- 
ente),  1;  Roswell  (and  20  and  50  miles  north),  17;  St.  Augustine  Plains 
(Catron  County,  12  miles  north  of  Monica  Spring),  10;  San  .Jon  (Quay 
County),  1;**  Santa  Rosa,  7. 

22  Univ.  Mich.  Mu.s.  Zool. 

«  Colorarto  Mus.  Nat.  Hist. 

^  E.  K.  Warren  collection. 

^  Kansas  Univ.  Mus.  Nat.  Hist. 

*"Acad.  Nat.  Sci.  Philadelphia. 

'^  State  Collf'ge,  New  Mexico. 

*  Cleveland  Mus.  Nat.  Hist. 

■»  Reading  (Pennsylvania)  Public  Mus. 


]^28  NORTH  AMERICAN  FAUNA  [No.  56 

Oklahoma:  Woodward,  7. 

Texas :  Alpine,  12 ;  Canadian,  1 ;  Colorado,  2 ;  Lipscomb,  1 ;  Mobeetie,  3 ;  Mona- 
bans  (Ward  County),  15;  Miami,  1;  Pecos,  4;  Presidio  County,  1;  Toyah- 
vale  (Reeves  County),  2;  Valentine,  3;  Van  Horn  (Culberson  County),  1. 

CITELLUS  SPILOSOMA  ANNECTENS   (Mekeiam) 

Padee  Island  Gkottnd  Sqijieeel 

Spermophilus   spilosoma   annectens   Merriam   Biol.    Soc.   Wasb.    Proe.    8 :  132, 

Dec.  28,  1893. 
[Gitellns  spilosoma]  annectens  Trouessart,  Cat.  Mamm.,  Sup.,  p.  340,  1904. 

Type. — Collected  at  "The  Tanks,"  12  miles  from  Point  Isabel, 
Padre  Island,  Tex.,  August  24,  1891,  by  Wm.  Lloyd ;  male  adult,  skin 
and  skull,  no.  Htlti  U.  S.  Natl.  Mus.  (Biological  Survey  collection) 
(orig.  no.  694). 

Range. — Lower  Rio  Grande  Valley,  Tex.,  and  Gulf  coast  section 
from  the  mouth  of  the  river  north  to  Nueces  River ;  Padre  and  Mus- 
tang Islands  (fig.  11).     Zonal  range:  Lower  Sonoran. 

External  characters. — Closely  similar  in  size  and  coloration  to  C.  s. 
major. 

Cranial  churacters. — Skull  closely  similar  to  that  of  major,  but 
averaging  slightly  longer,  and  slightly  broader  interorbitally ;  with 
slightly  narrower  brain  case ;  audital  bullae  smaller. 

Color. —  (Worn  summer  pelage)  :  Upper  parts  avellaneous  or  smoke 
gray ;  dorsal  spots  large  but  rather  indistinct ;  sides  white,  sometimes 
washed  with  cartridge  buff;  tail  above,  like  the  back,  shaded  on 
distal  portion  with  fuscous  and  edged  with  pale  cartridge  buff;  tail 
beneath,  cinnamon  or  light  pinkish  cinnamon;  feet  light  pinkish 
cinnamon  or  pinkish  buff ;  under  parts  soiled  whitish. 

Measurements. — Average  of  6  adults  from  type  locality :  Total  length,  229 
(220-234);  tail  vertebrae,  64.2  (55-75);  hind  foot,  35.4  (33-38).  SkuU: 
Average  of  7  adults  (6  males,  1  female)  from  tj^e  locality:  Greatest  length,  41 
(40.5^1.5)  ;  palatilar  length,  18.1  (17.5-19)  ;  zygomatic  breadth,  23.8  (23.2-24.4)  ; 
cranial  breadth,  18  (17.6-18.5)  ;  interorbital  breadth,  9  (8.5-9.3)  ;  postorbital 
constriction,  13.1  (12.1-14.1) ;  length  of  nasals,  14.1  (13.4-14.6)  ;  maxillary  tooth 
row,  13.1   (12.1-14.1). 

Remarks. — The  Padre  Island  ground  squirrel  is  evidently  an  off- 
shoot of  major  and  shows  no  close  relationship  to  the  darker  and  more 
finely  spotted  forms  in  Mexico.  Some  form  of  this  species  has  been 
reported  from  various  points  along  the  Rio  Grande,  up  as  far  as  the 
mouth  of  the  Pecos  River,  but  no  specimens  are  available  from  that 
part  of  the  valley ;  therefore  it  is  uncertain  whether  or  not  the  range 
of  annectens  meets  that  of  major. 

Specimens  examined.- — Total  number,  30,  as  follows: 

Texas :  Mustang  Island,  2 ;  ^*  Norias,  2 ;  ^^  Padre  Island,  21 ;  Rio  Grande  River 
(at  mouth),  1;  Sarita,  4..'^^ 

CITELLUS  SPILOSOMA  PRATENSIS  (Mereiam) 

Park  Spotted  Gbound  Squiebel 

(Pls.  25,  B\  30,  B) 

Spermophilus  spilosoma  pratensis  Merriam,  North  Amer.  Fauna  3 :  55,  Sept.  11, 

1890. 
Spermophilus  spilosoma  obsidianus  Merriam,  North  Amer.  Fauna  3 :  56,  1890 

(Cedar  Belt,  northeast  of  San  Francisco  Mountain,  Ariz.). 
[Citellus  spilosomaJi  pratensis  Trouessart,  Cat.  Mamm.,  Sup.,  p.  340,  1904. 


2»«Acad.  Nat.  Scl,  Philadelphia. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  129 

Type. — Collected  at  north  base  of  San  Francisco  Mountain  (pine 
plateau),  Ariz.,  August  5,  1889,  by  C.  Hart  Merriam  and  Vernon 
Bailey;  female  adult,  skin  and  skull,  no.  mif ,  U.  S.  Natl.  Mus. 
(Biological  Survey  collection)   (orig.  no.  285). 

Range. — North-central  Arizona,  between  the  Grand  Canyon  and 
the  Mogollon  Plateau;  west  to  Seligman  and  Aubrey  Valley  (fig.  11). 
Zonal  range:  Upper  Sonoran  and  Transition. 

External  characters. — Similar  to  C.  s.  canescens  but  smaller,  with 
shorter  tail  and  hind  feet ;  upper  parts  darker ;  dorsal  spots  smaller ; 
tail  darker,  with  more  black  on  distal  portion. 

Cranial  characters. — Skull  similar  to  that  of  canescens .,  but  de- 
cidedly smaller ;  much  smaller  than  that  of  C.  s.  major. 

Color. — General  tone  of  upper  parts  near  snuff  brown  or  verona 
brown,  many  of  the  hairs,  especially  on  shoulders,  tipped  with 
whitish,  producing  a  hoary  effect ;  back  thickly  sprinkled  with  small 
white  spots  which  become  less  distinct  or  obsolete  on  the  shoulders; 
sides  of  nose  and  face  grayish ;  eye  ring  white ;  sides  of  body  some- 
times faintly  washed  with  pale  cartridge  buff ;  tail  above,  dark  fawn 
color  or  mikado  brown,  the  distal  half  mainly  black  or  fuscous  black, 
edged  with  pinkish  buff  or  buffy  white;  tail  beneath,  pinkish  buff, 
cinnamon  buff,  or  pinkish  cinnamon,  more  or  less  mixed  with  grayish 
white  and  fuscous  black;  feet  whitish,  washed  with  cartridge  buff; 
under  parts  white. 

Measurements. — Average  of  10  adults  from  San  Francisco  Mountain  and 
vicinity  of  FlagstafP,  Ariz.:  Total  length,  195.8  (185-210)  ;  tail  vertebrae.  61.1 
(55-68);  hind  foot,  30.5  (28-33).  SknU:  Average  of  11  adults  (3  males,  8 
females)  from  San  Francisco  Mountain,  Flagstaff,  and  Walnut  Canyon: 
Greatest  length,  35.5  (34.1-36.3)  :  palatilar  length,  15.7  (15-16.5)  :  zygomatic 
breadth,  20.9  (20.2-21.7)  ;  cranial  breadth,  17  (16.4-17.5)  ;  interorbital  breadth, 
7.3  (6.9-8)  ;  postorbital  constriction.  12.5  (11.5-13.6)  ;  length  of  nasals,  12.1 
(11.2-13.2)  ;  maxillary  tooth  row,  6.6   (6.2-7.8). 

Remarks. — The  park  spotted  ground  squirrel  is  the  smallest  form 
in  the  group.  Although  most  resembling  canescens.,  there  is  no  evi- 
dence of  intergradation  with  that  race,  the  ranges  of  the  two  ap- 
parently being  separated  by  the  Mogollon  Plateau.  Intergradation 
with  major  is  suggested,  though  not  clearly  shown  by  three  specimens 
from  Gallup  and  Thoreau,  N.  Mex.,  which  agree  closely  with 
pratensis  in  external  characters  but  have  larger  skulls.  On  the 
Painted  Desert,  this  form  passes  into  the  subspecies  C.  s.  crypto- 
spilotns. 

Specimens  examined. — Total  number,  62,  as  follows : 

Arizona:  Aubrey  Valley  (Hualpai  Indian  Reservation),  1;  Deadmans  Flat 
(northeast  of  San  Francisco  Mountain),  9;'"  Flagstaff  (including  9  miles 
northwest  and  12  miles  northeast),  7;  Grand  Canyon  (Bass  Camp  and 
Trash  Tank),  8;  Kendrick  Peak  (20  miles  northwest  of  Flagstaff),  1;  San 
Francisco  Mountain,  20;  Seligman,  1;  Walnut  Canyon  (Coconino  Natl. 
Forest).  15. 


3"  Mus.  Vert.  Zool. 


154970—38- 


230  NORTH  AMERICAN  FAUNA  [No.  56 

CITELLUS  SPILOSOMA  CRYPTOSPILOTUS   (Mesitjiam) 
Desert  Spotted  Gkound  Squirrel 

Spermophilus   cryptospilotus   Merriam,    North   Amer.    Fauna   3 :  57,    Sept.    11, 

1890. 
Anlsonyx  (Xerospermophilns)  cryptospilotus  Allen,  Amer.  Mus.  Nat.  Hist.  Bull. 

7:  240,  1895. 
\_Citellus]  cryptospilotus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  1904. 

Type. — Collected  at  "Tenebito"  [=Dinnebito]  Wash,  Painted 
Desert,  Ariz.,  August  17,  1889,  by  C.  Hart  Merriam;  male  juv.,  skin 
and  skull  no.  ^^f,  U.  S.  Natl.  Mus.  (Biological  Survey  collection) 
(orig.  no.  374). 

Range. — Northeastern  Arizona,  southeastern  Utah,  southwestern 
Colorado,  and  northwestern  New  Mexico ;  north  to  Monticello,  Utah ; 
east  to  Thoreau,  N.  Mex. ;  south  to  Holbrook,  Ariz.;  west  to  the 
Little  Colorado  River  (fig.  11).  Zonal  range:  Upper  and  Lower 
Sonoran. 

External  characters. — Similar  in  size  to  C.  s.  pratensis.f  but  colora- 
tion paler  and  more  reddish  (less  brownish)  ;  similar  to  C.  s.  major 
but  much  smaller ;  dorsal  spots  smaller  and  more  numerous. 

Cranial  characters. — Skull  similar  to  that  of  fratensis;  smaller 
than  that  of  major. 

Color. — Upper  parts  fawn  color  or  avellaneous,  rather  heavily 
sprinkled  on  hinder  back  with  small  whitish  spots ;  sides  washed  with 
pinkish  buff  or  cartridge  buff;  feet  cartridge  buff;  tail  above,  like 
the  back  and  edged  with  pinkish  buff  with  a  fuscous  patch  near  the 
tip ;  tail  beneath,  pinkish  buff  or  light  pinkish  cinnamon ;  under  parts 
white. 

Measurements. — Average  of  6  adults  from  Painted  Desert,  Ariz. :  Total  length, 
199.5  (190-210);  tail  vertebrae,  65  (58-72);  hind  foot,  31.8  (31-33).  Skull: 
Average  of  14  adults  from  Painted  Desert  (4)  and  Oraibi  (10)  :  Greatest 
length,  36.2  (35.1-36.8)  ;  palatilar  length,  15.9  (14.5-16.5)  ;  zygomatic  breadth, 
21.0  (20.9-22.4)  ;  cranial  breadth,  17.5  (16.3-1S.4)  ;  interorbital  breadth,  7.9 
(7.2-8.6)  ;  postorbital  constriction,  12.9  (11.9-13.8)  ;  length  of  nasals,  12.5 
(11.7-13.5)  ;  maxillary  tooth  row,  7   (6.3-7.4). 

Remarks. — The  desert  s])otted  ground  squirrel  is  closely  related  to 
'  pratensis,  its  nearest  neighbor  on  the  west.  The  series  from  Wins- 
low,  Ariz.,  indicates  intergradation  with  major;  specimens  in  the 
cinnamon  phase  agree  in  color  with  cryptospilotus  while  others  in 
the  drab  phase  closely  resemble  major;  the  skulls  are  somewhat 
larger  than  those  of  typical  cryptospilotus. 

Specimens  examined. — Total  number,  42,  as  follows : 

Arizona:  Chin  Lee  (15  miles  southwest,  Apache  County),  1;  Holbrook,  7;  Oraibi 
(Navajo  County),  13;  Painted  Desert,  6  (Diunebito  Wash,  1;  Moa  Ave,  4; 
Tuba,  1)  ;  Winslow,  7. 

Colorado:  McElmo  Creek  (south  of  Cortez,  Montezuma  County),  2.'^ 

New  Mexico:  Gallup,  3;  Thoreau  (McKinley  County),  1. 

Utah:  Lockerby  (San  Juan  County),  1;  Monticello  (San  Juan  County),  1. 

CITELLUS  SPILOSOMA  OBSOLETUS    (Kennicott) 

Kbnnicott's  Spotted  Ground  Sqihebeil 

Sperriiophilns  ohsoletus  Kennicott,  Acad.  Nat.  Sci.  Phila.  Proc.  1863:  157. 
ICitellusI  obsoletus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  340,  1904. 


81  Colorado  Agr.  College. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  131 

Type. — None  designated;  Lyon  and  Osgood  (1909,  p.  169),  list 
seven  specimens  in  the  United  States  National  Museum  collection  as 
being  the  material  used  by  Kennicott;  no.  xrWs:  U.  S.  Natl.  Mus., 
is  hereby  designated  as  lectotype ;  9 ,  skin  and  skull ;  collected  50 
miles  west  of  Fort  Kearney,  Nebr.,  August  9,  1857,  by  J.  G.  Cooper 
(orig.  no.  44). 

Range. — Sandhill  region  of  Nebraska;  north  to  Todd  County, 
S.  Dak. ;  east  to  Neligh,  Nebr. ;  south  to  Tuttle,  Colo. ;  west  to  Platte 
County,  Wyo.,  and  Greeley,  Colo,  (fig.  11).  Zonal  range:  Upj)er 
Sonoran. 

Exter'nal  characters. — Similar  to  C.  s.  major  but  averaging  smaller ; 
dorsal  spotting  less  distinct  and  tending  to  become  obsolete,  the 
white  spots  usually  more  distinctly  edged  with  black;  drab  phase 
predominating. 

Cranial  characters. — Skull  similar  to  that  of  major  but  averaging 
smaller,  with  smaller  audital  bullae. 

Color. — Upper  parts  smoke  gray,  light  drab,  or  avellaneous ;  dorsal 
white  spots  of  moderate  size,  but  scattered  and  more  or  less  indis- 
tinct, often  nearly  obsolete;  most  of  the  hairs  on  back  tipped  with 
black  or  fuscous  black,  these  tips  tending  to  form  irregular  and 
more  or  less  indistinct  spots,  especially  on  hinder  back;  patch  on 
front  of  face  pinkish  cinnamon  or  light  vinaceous  cinnamon;  sides 
of  nose  and  eye  ring  white ;  sides  of  body  washed  with  pale  cartridge 
buff;  front  feet  pinkish  buff;  hind  feet  whitish,  washed  with  light 
pinkish  cinnamon  or  cartridge  buff;  tail  above,  vinaceous  fawn  or 
wood  brown,  shaded  on  distal  portion  with  fuscous  and  edged  with 
cartridge  buff;  under  parts  white. 

Measurements. — Average  of  10  adults  (5  males,  5  females)  from  Nebraska: 
Total  length,  214.3  (197-226)  ;  tail  vertebrae,  64.B  (56-79)  ;  hind  foot,  31.8 
(30-34).  Skull:  Avei-age  of  10  adults  (5  males,  5  females)  from  Nebraska: 
Greatest  length,  38.9  (37.7-39.9)  ;  palatilar  length,  17.4  (16.5-18)  ;  zygomatic 
breadth,  23  (22.2-23.6)  ;  cranial  breadth,  17.6  (17-18.2)  ;  interorbital  breadth, 
7.8  (7-8.2)  ;  postorbital  constriction,  13.2  (12.1-13.8)  ;  length  of  nasals,  13.3 
(12.5-13.9)  ;  maxillary  tooth  row,  7.2    (6.9^7.5). 

Remarks. — Kennicott  recognized  the  near  relationship  of  this  form 
to  C.  s.  spiloso7na  when  he  described  it  in  1863.  Not  until  recently, 
however,  when  large  series  of  specimens  from  many  localities  have 
been  obtained,  has  it  become  clear  that  it  is  connected  with  the  more 
southern  races  by  a  nearly  complete  series  of  intergrades. 

/Specimens  examined. — Total  number,  33,  as  f oIIoavs  : 

Colorado:  Avalo  (10  miles  east,  Logan  County),  1;  Greeley,  1;  Merino  (Logan 
County),  1;'"  Sterling,  3;  Tuttle   (Kit  Carson  County),  1;  Wmy,  2. 

Kansas:  St.  Francis  (9  miles  northwest),  1.^ 

Nebraska:  Cherry  County,  2;  Fort  Kearney  (50  miles  west),  1;  Kennedy 
(Cherry  County),  6;  Lincoln  County,  2;  Neligh,  1;  O'Fallons  Bluff  (Lincoln 
Coimty),  1;  Simeon  (Cherry  County).  1;  Valentine,  4. 

South  Dakota:  White  River  (south  fork),  1. 

Wyoming:  Little  Bear  Creek  (20  miles  southeast  of  Chugwater),  1;  Wheat- 
land, 1;  Fort  Laramie  (Goshen  County),  1;  Spoon  Butte  (Goshen  County), 
1. 


•■"=  Clevelanfl  Mus.  Nat.  Hist. 
^Kansas  Univ.  Mus.  Nat.  Hist. 


132  NORTH  AMERICAN  FAUNA  [No.  56 

CITELLUS  PEROTENSIS  (Mebeiam) 

Peeote  Ground  Squirrel 

(Pis.  25,  D;  30,  D) 

SpermopMlus  perotensis  Merriam,  Biol.  Soc.  Wash.    Proc.  8 :  131,  Dec.  28,  1893. 
[Citellus]  perotensis  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  .4:  145,  1904. 

Type. — Collected  at  Perote,  Vera  Cruz,  Mexico,  June  8,  1893,  by 
E.  W.  Nelson  and  E.  A.  Goldman;  female  adult,  skin  and  skull,  no. 
54274,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig.  no.  4976). 

Range. — Known  only  from  the  extreme  eastern  border  of  the 
Mexican  tableland  in  the  vicinity  of  Perote,  Vera  Cruz,  at  an  alti- 
tude of  7,800  or  7,900  feet ;  ranges  to  a  point  10  miles  south  of  Perote 
and  eastward  to  within  a  few  miles  of  Las  Vigas  (fig.  11).  Zonal 
range:  Upper  Sonoran. 

External  characters. — Similar  to  G.  spilosoma  pallescens  but  larger, 
with  shorter  tail;  coloration  more  yellowish  (less  pinkish);  dorsal 
spots  buffy  rather  than  white,  smaller  and  less  conspicuous  (often 
nearly  obsolete);  under  parts  buffy  instead  of  white;  head  marked 
with  blackish. 

Cranial  characters. — Skull  similar  to  that  of  G.  s.  spilosoma  but 
larger,  with  relatively  narrower  and  higher  brain  case ;  audital  bullae 
broader  and  more  flattened;  molariform  teeth  heavier. 

Golor. —  (Type,  in  worn  pelage,  June  8)  :  General  tone  of  upper 
parts  dull  clay  color,  varied  on  hinder  back  with  fuscous  and  very 
indistinctly  speckled  with  pinkish  buff ;  top  of  head  and  face  washed 
with  fuscous  black,  sides  of  head  washed  with  smoke  gray;  eyelids 
buffy  white ;  sides  of  body  pinkish  buff  or  cartridge  buff ;  under  parts 
and  feet  similar  or  slightly  paler;  tail  above,  similar  to  the  back, 
but  distal  two-thirds  mixed  with  blackish  and  tipped  with  pale 
carti'idge  buff ;  tail  beneath,  pinkish  buff,  bordered  at  distal  end  with 
blackish. 

Variation. — Other  specimens  taken  in  June  are  considerably  paler 
than  the  type,  the  general  tone  of  upper  parts  varying  from  wood 
brown  to  drab,  and  some  of  the  immature  individuals  are  more  con- 
spicuously spotted. 

Measurements. — Average  of  11  adults  from  type  locality:  Total  length,  250.4 
(243-261)  ;  tail  vertebrae,  70.5  (57-78),  hind  foot,  38.7  (38-40).  STcull:  Great- 
est length,  43.5  (42.2^4.5)  ;  palatilar  length,  20.6  (20-21.5)  ;  zygomatic  breadth, 
26.4  (25.2-27.3)  ;  cranial  breadth,  19.5  (19.1-20)  ;  interorbital  breadth,  9.3 
(8.8-9.8)  ;  postorbital  constriction,  14  (13.3-14.7)  ;  length  of  nasals,  15.5 
(14.5-16.5);  maxillary  tooth  row,  8.7   (8.3-9). 

Remarks. — The  Perote  ground  squirrel — the  largest  member  of 
the  spilosoma  group — is  clearly  related  to  G.  s.  spilosonia  but  appar- 
ently does  not  intergrade  with  it.  Its  range  apparently  is  restricted 
to  the  high  plains  at  the  extreme  eastern  border  of  the  Mexican 
tableland.  As  pointed  out  by  Merriam,  this  species  bears  a  general 
external  resemblance  to  G.  richardsonii  elegans^  but  differs  widely 
from  it  in  skull  characters  and  belongs  in  another  subgenus. 

Specimens  examined. — Total  number,  16,  from  type  locality. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


133 


POLIOCITELLUS,  subgenus  nov. 

[Characters  and  description  on  p.  42] 

CITELLUS  FRANKLINII   (Sabine) 

Fbanklin's  Ground  Squibbex 

(PI.  6) 

Arctomys  franklinii  Sabine,  Linn.  Soc.  London  Trans.  13:  587,  1822. 

Arctomys   (Spermophilus)   franklinii  Richardson,  Fauna  Boreali-Amer.  1:  168, 

1829. 
Spermophilus  franklini  Lesson,  Manual  Mamm.,  p.  244, 1827. 
[Citellus]  franklini  Trouessart,  Cat.  Mamm.,  Sup.,  p.  342,  1904. 

Tyjje. — Collected  at  Carlton  House,  Saskatchewan,  probably  by 
John  Eichardson  (Preble,  1908,  p.  165) ;  male,  skin  and  skull,  no.  61a, 
British  Museum. 

Range. — Great  Plains  region  of  southern  Canada  and  the  upper 
Mississippi  and  Missouri  Valleys;  north  to  Athabaska  Landing, 
Alberta;  east  to  Lake 
Winnipeg,  Manitoba, 
southeastern  Wiscon- 
sin, and  northwestern 
Indiana;  south  to 
southeastern  Kansas, 
central  Missouri,  and 
central  Illinois;  w^est 
to  Edmonton,  Alberta, 
the  Missouri  Valley  in 
North  Dakota  and 
South  Dakota,  central 
Nebraska  and  central 
Kansas ;  introduced  in 
Ocean  County,  N.  J. 
(fig.  12).  Zonal 
range:  Transition  and 
Upper  Austral. 

External  c  h  ar  ac- 
ters. — About  the  size 
of  G.  parryii  plesius 
but  tail  longer  ; 
ears  larger,  suborbicu- 
lar. 

Cranial  characters. — Skull  long  and  narrow,  with  flattened  super- 
ior outline,  quite  unlike  any  member  of  the  subgenus  Citellus;  some- 
what resembling  G.  heecheyi  but  rostrum  longer ;  brain  case  narrower 
and  less  inflated;  temporal  region  more  constricted;  and  anterior 
border  of  zygomatic  notch  reaching  only  to  posterior  border  of  m  ^. 

Golor. — Summer  pelage  (topotypes,  July)  :  Head  grayish,  the 
bases  of  the  hairs  fuscous  black,  tips  grayish  white.  (The  color  tone 
of  the  head  varies  with  the  amount  of  wear,  worn  pelages  being  de- 
cidedly darker  than  fresh  pelages  because  of  the  exposure  of  the 
dark  bases  of  the  hairs.)  Dorsum  tawny  olive  or  clay  color,  more 
or  less  shaded  with  fuscous;  sides  pinkish  buff  or  cinnamon  buff 
mixed  with  grayish  white;  thighs  pale  smoke  gray,  shaded  with 
pinkish  buff  and  fuscous ;  front  feet  pinkish  buff ;  hind  feet  grayish 


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FiQDHB  12. — Distribution  of  Citellus  franklinii. 


J34  NORTH  AMERICAN  FAUNA  [No.  56 

white,  shaded  with  tilleul  buff ;  tail  above  and  below,  blackish  mixed 
with  tilleul  buff,  overlaid  and  bordered  with  creamy  white;  under 
parts  pinkish  buff  or  buffy  white. 

Variation. — Certain  specimens  in  worn  summer  pelage  are  de- 
cidedly darker  above  than  those  in  the  fresh  pelage  described,  the 
general  tone  of  the  upper  parts  being  sayal  brown  or  ochraceous 
tawny;  in  these  the  exposure  of  the  fuscous  bases  of  the  hairs  pro- 
duces the  effect  of  spotting.  Winter  pelage  (North  Dakota  speci- 
mens in  May)  :  Similar  to  fresh  summer  pelage  but  paler,  the  tips 
of  the  hairs  on  upper  parts  pinkish  buff,  the  sides  paler  and  more 
whitish;  feet  paler  and  less  buffy.  Specimens  taken  in  April 
(Nebraska)  and  May  (Alberta),  being  apparently  in  winter  pelage, 
are  darker  than  those  described  above,  the  general  tone  of  the  upper 
parts  being  clay  color. 

Measurements.— AN&Yaige  of  6  adult  males  from  Saskatchewan  (type  locality) 
and  Alberta:  Total  length,  388.7  (381-397);  tail  vertebrae,  144.7  (136-153); 
hind  foot,  55.1  (53-57.5)  ;  ear  from  notch,  10.5  (10-11).  Average  of  5  adult 
females  from  Saskatchewan  (Wingard  and  Indian  Head)  :  Total  length,  384.6 
(363-401)  ;  tail  vertebrae,  146.8  (133-156)  ;  hind  foot,  52.8  (51-55)  ;  ear  from 
notch,  10.5  (10-11).  Skull:  Average  of  5  adult  males  from  Saskatchewan  and 
Alberta:  Greatest  length,  54.2  (53-54.6)  ;  palatilar  length,  26.3  (25-27)  ;  zygo- 
matic breadth,  31.4  (31-32.1)  ;  cranial  breadth,  21.1  (20.9-21.3)  ;  interorbital 
breadth,  12.3  (12.1-12.7)  ;  postorbital  constriction,  13.1  (12.8-13.4)  ;  length  of 
nasals,  18.4  (17.6^18.8)  ;  maxillary  tooth  row,  10.3  (10.2-10.4).  Average  of  5 
adult  females  from  Saskatchewan  (Wingard  and  Indian  Head)  :  Greatest  length, 
53.2  (52.1-55.1)  ;  palatilar  length,  25.8  (25-27)  ;  zygomatic  breadth,  30.6  (30.1- 
31.4)  ;  cranial  breadth,  20.5  (20.2-20.7)  ;  interorbital  breadth,  12  (11.4-12.5)  ; 
postorbital  constriction,  13.1  (13-13.4)  ;  length  of  nasals,  18.4  (17.8-19.6)  ; 
maxillary  tooth  row,  10.4  (10.2-10.7). 

Remarks. — Franklin's  gi'ound  squirrel  is  a  very  distinct  species, 
having  no  close  relatives  and  although  it  exhibits  considerable  varia- 
tion in  color,  these  differences  are  individual  and  not  correlated  with 
geographical  distribution.  It  was  introduced  into  New  Jersey  at 
Tuckerton  in  May  1867,  a  single  pair  brought,  from  Illinois  having 
escaped  from  their  cage  and  established  themselves  in  the  sandy  fields. 
Since  then  they  have  spread  northward  as  far  as  Manahawken  and 
westward  to  Speedwell  (Stone,  1908,  p,  80). 

Specimens  examined. — Total  number,  160,  as  follows : 

Alberta:  Edmonton,  1;  Sturgeon  River  (25  miles  north  of  Edmonton),  2. 

Ilimois:  West  Northfield  (Cook  County),  1.'' 

Indiana:  Benton  County,  1;  Lake  Village  (Newton  County),  6;  ^^  North  Liberty 

(St.  Joseph  County),  3.'" 
Iowa:  Ames,  2;  Charles  City,  1;="  Clay  County,  9;''  Milford,  1;**  Wall  Lake, 

Kansas:  Manhattan,  1;  Onaga,  1. 

Manitoba:  Carberry,  3;  Manitoba  House,  1;  Winnipeg,  1. 

Minnesota :  Browns  Valley,  4 ;  Cass  Lake,  2 ;  Elk  River,  10 ;  Fort  Snelling,  1 ;  ^' 

Heron  Lake,  2;  Ortonville,  10. 
Nebraska:  Ames    (Dodge  County),  1;   Columbus,  2;  Kearney,  1;  Niobrara,  1; 

Verdigris,  1. 
New  Jersey:  Tuckerton,  5. 
North  Dakota:  Blackmer   (Richland  County),  4;  Devils  Lake,  6;  Pairmount 

14;  Fargo,  1;  Fish  Lake  (Benson  County),  4;  Grafton,  1;  Grand  Forks,  1 

Harwood   (Cass  County),  3;  Kathryn  (Barnes  County),  1;  La  Moure,  1 


3*  Univ.  Michigan  Mus.  Zool. 
^  P.  F.  ETiekie  collection. 
2'  Univ.  of  Notre  Dame, 
s^  Dayton  Stoner  collection. 
38  Field  Mus.  Nat.  Hist. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


135 


Larimore,  2;   Oakes,  3;  Pembina,   5;    Spring  Lake    (Rolette  County),   1; 

Stump  Lake,  2 ;  Turtle  Mountains,  2  ;  **  Walhalla,  2. 
Ontario :  Rainy  River,  7/° 
Saskatchewan :  Carlton,  4 ;  Indian  Head,  3 ;  Oxbow,  1 ;  Prince  Albert,  1 ;  ^  Win- 

gard,  5. 
South  Dakota:  Flandreau,  1;   Fort  Sisseton   (Marshall  County),  2;  Scotland, 

1 ;  Vermillion,  1. 
Wisconsin:  Delavan,  4. 

Subgenus  OTOSPERMOPHILUS  Brandt 

[Characters  on  p.  43] 
COLOE  PATTEHN 

In  the  typical  species  and  its  near  relatives  the  color  of  the  upper 
parts  is  a  mixture  of  various  shades  of  buif,  black,  and  white,  the 
hinder  back  usually  presenting  a  mottled  appearance;  some  races 
have  prominent  whitish  shoulder  patches,  others  have  solid  black 
areas  on  the  head  or  anterior  back ;  the  bases  of  the  hairs  are  fuscous ; 
the  tail  hairs  are  banded  with  black. 


PBXAGE  AND   MOLT 


worn. 


The  pelage  is  full  and  soft  when  fresh,  shorter  and  harsher  when 
There  is  but  one  molt  annually,  which  may  occur  at  any 
time  from  early  in  May  to  early  in  September,  depending  in  part 
on  the  climate.     Breeding  females  are  likely  to  molt  later  than  males. 


Key  to  Species  and  Subspecies 

^  Head  black  or  brown. 

b.^  Shoulders  and  fore  back  solid  black  or  brown huclcleyi 

b.^  Shoulders  and  fore  back  mixed  with  whitish, 
c*  Upper  parts  brownish  or  huffy. 

d.}  Size  small  (skull  length  less  than  60  mm) atricapillus 

d.^  Size  large(skull  length  more  than  60  mm). 

f}  Head  black coucliii 

f.^  Head   brown rupestris 

c.^  Upper  I'.arts  blackish varicyatufs 

-  Head  mixed  with  buffy. 
&.'  Nape  and  shoulders  with  a  dark  median  area. 

c.^  Fore  back  with  a  blackish  patch douglusii 

c.^  Fore  back  without  a  blackish  patch. 

d.^  White  shoulder  patches  indistinct nesioticvs 

d."  White  shoulder  patches  distinct, 
e.'  Upper  parts  darker. 

f}  Feet  wliitish sierrae 

f.^  Feet  buffy. 

g}  Under  parts  darker  (more  buffy) beecheyi  ( 

(J.'  Under  parts  paler  (more  whitish) nudipcs 

e.^  Upper  parts  paler. 

f}  Size  larger  (skull  length,  55-62  mm) fishcri 

f.^  Size  smaller    (skull  length,  52-GO  mm) parvulus 

b.^  Nape  and  shoulders  without  dark  median  area, 
c*  Upper  parts  blackish. 

d.^  Head  more  blackish rariegattis 

d.'  Head  more  buffy tularosac 

c?  Upper  parts  brownish  or  buffy. 

d}  Size  smaller  (skull  length  of  9  less  than  57  mm) rnpinarnm 

d.'  Size  larger  (skull  length  of  9  more  than  57  mm). 

f.'  Hinder  back   more   tawny utah 

f.^  Hinder  back  more  buffy grammnrus 


p.  141). 


p. 161). 


P- 


130). 
138). 
136). 


150). 
160). 


p. 153). 


14S). 
158). 

154). 
156). 


136). 
145). 


p. 159). 


146). 
142). 


**  Univ.  Michigan  Mus.  Zool. 
»« Field  Mus.  Nat.  Hist. 
*•  Royal  Ontario  Mus. 


236  NORTH  AMERICAN  FAUNA  [No.  56 

CITELLUS  VARIEGATUS  (Eexleben) 
[Synonymy  under  subspecies] 

Speciiic  characters. — Size  large;  hind  foot,  53-65  mm;  tail,  174- 
263;  skull  length,  56-67.7.  Skull  somewhat  resembling  that  of 
C.  parryii  but  differing  in  the  characters  of  the  subgenus ;  dorsal  pro- 
file nearly  flat ;  brain  case  and  interorbital  region  relatively  broader ; 
parietal  ridges  meeting  at  posterior  end  of  cranium  to  form  a  slight 
crest ;  rostrum  relatively  broad,  tapering  gradually ;  postorbital  proc- 
esses stout,  decurved;  supraorbital  borders  of  frontals  slightly  ele- 
vated ;  zygomata  less  widely  expanded ;  audital  bullae  relatively  long 
and  narrow,  the  meatus  tube  very  short;  upper  incisors  stout,  not 
prognathous;  molariform  teeth  low-crowned  (as  described  under 
subgeneric  characters,  p.  43). 

Color. — Head  varying  from  pinkish  buff  or  pinkish  cinnamon  to 
seal  brown  and  fuscous  black;  upper  parts  varying  from  grayish 
white  mixed  with  cinnamon  buff  to  snuff  brown,  mikado  brown,  bone 
brown,  and  dark  blackish  brown;  in  some  races  the  head  and  fore 
back,  in  others  the  whole  dorsal  surface  is  blackish ;  the  tail  is  mixed 
black  or  brown  and  buffy  white. 

CITELLUS  VARIEGATUS  VARIEGATUS  (Ebxleben) 

Mexican  Rock  Sqtjierei, 

(PI.  7) 

[Sciurusi  variegatus  Erxleben,  Syst  Regni,  Anim  1 :  421,  1777. 

Sciurus  huccatus  Lichtenstein,  Abhandl.  k.  Akad.  Wiss.  Berlin,  1827  (1830), 
p.  117. 

Spermophilus  macrourus  Bennett,  Zool.  Soc.  London  Proc.  1833;  41.  ("West- 
Mexico" — in  Zool.  Society  register.) 

Spermophilus  variegatus  Nelson,  Science  (n.  s.)  8:  898,  1898. 

[Citellus]  variegatus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  4 :  148,  1904. 

Otospermophilus  variegatus  Miller,  U.  S.  Natl.  Mus.  Bull.  128:  181,  1924. 

Type. — None  designated;  type  locality  fixed  at  Valley  of  Mexico 
near  the  City  of  Mexico  (Nelson,  1898,  p.  898) . 

Range. — (I^entral  Mexico,  from  southern  Zacatecas  and  San  Luis 
Potosi  south  to  Michoacan  and  the  Valley  of  Mexico ;  west  to  Colima, 
Jalisco,  and  Nayarit  (fig.  13).  Zonal  range:  Upper  and  Lower 
Sonoran. 

External  characters. — Size  large;  tail  long  (nearly  half  the  total 
length)  ;  head  blackish,  more  or  less  mixed  with  buff;  general  tone 
of  upper  parts  gray,  more  or  less  heavily  mixed  with  blackish ;  tail 
mixed  black  and  white. 

Cranial  characters.— ^]sxi\\  of  large  size;  zygomata  heavy  and 
rather  widely  expanded ;  interorbital  region  broad ;  postorbital  proc- 
esses heavy ;  nasals  ending  posteriorly  on  a  line  with  ascending  arms 
of  premaxillae  or  slightly  beyond. 

Color. — Winter  pelage  (Valley  of  Mexico)  :  Sides  of  nose  pinkish 
buff  or  tilleul  buff;  front  and  sides  of  face  brownish,  mixed  with 
buffy  white;  eyelids  broadly  margined  with  dull  white;  crown  and 
occiput  dark  blackish  brown ;  hairs  on  the  dorsal  surface  fuscous  or 
fuscous  black  at  base,  banded  with  dull  white  or  pinkish  buff,  some 
tipped  with  blackish;  feet  drab  gray,  tinged  with  fuscous;  thighs 
washed  with  cinnamon  buff  or  ochraceous  tawny;  tail  blackish, 
mixed  with  buffy  white  and  cinnamon  buff;  under  parts  grayish 
white  or  cinnamon  buff. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


137 


Variation. — The  majority  of  the  specimens  of  this  race  have  more 
or  less  black  on  the  head*  some  however,  have  the  hairs  on  the  head 
fuscous  basally ,  tipped  with  pinkish  buff ;  the  amount  of  black  show- 
ing on  the  dorsal  surface  varies  considerably'^,  some  being  only 
slightly  darker  than  certain  specimens  of  G.  v.  grammurus. 

Molt. — The  molting  season  covers  a  considerable  part  of  the  year ; 
in  a  specimen  from  Nayarit,  taken  April  12,  new  pelage  covers  the 
head  and  anterior 
half  of  the  back ;  one 
from  Guanajuato, 
June  20,  and  one 
from  Michoacan, 
July  14,  have  nearly 
completed  the  molt; 
several  from  San 
Luis  Potosi,  August 
17,  are  badly  worn 
and  new  pelage  is 
coming  in  on  the  an- 
terior upper  parts ; 
one  from  Guanajua- 
to, November  7,  had 
acquired  a  fresh  pel- 
age on  the  head  and 
the  posterior  half  of 
the  body,  leaving  a 
worn  area  of  old  pel- 
age on  the  shoulders 
and  nape. 

Measurements.— Kvev- 
age  of  8  adult  males 
from  central  Mexico 
(Federal  District,  Pueb- 
la,  and  Michoacan)  :  To- 
tal length.  499  (470- 
f)20)  ;  tail  vertebrae, 
227.4  (197-249)  ;  hind 
foot,  62.7  (5^-65)  ;  ear 
from  notch  (dry),  18.9 
(18-20).  Average  of  7 
adult  females  from  same 
region  :  Total  length,  479 
(447-510)  ;  tall  vertebrae,  222  (212-233)  ;  hind  foot,  60  (57-64)  ;  ear  from  notch, 
19.2  (19-19.5,  two  specimens  only) .  Skull:  Average  of  9  adult  males  from  central 
Mexico  (Federal  District,  Puebla,  Michoacan,  Jalisco,  San  Luis  Potosi,  and  Co- 
lima)  :  Greatest  length,  65.0  (64.1-67.7)  ;  palatilar  length,  31.5  (29.8-33)  ;  zygo- 
matic breadth,  40.5  (38.1-41.8)  ;  cranial  breadth,  26.1  (25.5-26.6)  ;  interorbital 
breadth,  16.9  (15.5-18.1)  ;  postorbital  constriction,  17.7  (16.7-18.8)  ;  length  of 
nasals,  23.8  (22.4-24.5)  ;  maxillary  tooth  row,  13.4  (12.8-14).  Average  of  7 
adult  females  from  the  same  region:  Greatest  length,  62.1  (59-65.7)  ;  palatilar 
length,  29  (28.5-32.5)  ;  zygomatic  breadth,  38.7  (36-42.4)  ;  cranial  brcadtli,  25.5 
(24.3-26.7)  ;  interorbital  breadth,  15.7  (13.7-18.8)  ;  postorbital  constriction,  17.9 
(16.4-19.6)  ;  length  of  nasals,  21.8  (21-22.9)  ;  maxillary  tooth  row,  13.1  (12.7-13.7) . 

Remarks. —Poison  (1898,  p.  898)  has  shown  the  pertinence  of  Erx- 
leben's  name  Sciurus  variegatus  to  the  Mexican  rock  squirrel,  and  as 
suggested  by  him,  this  animal  proves  to  be  connected  subspecifically 
with  G.  V.  couchii  and  G.  v.  grammurus,  as  well  as  with  G.  v.  rwpestris. 


FiGDRB  13. — Distribution  of  Citellus  atricapillus  and  of  the 
sub.ipecies  of  C.  variegatus:  1,  C.  v.  grammurua;  2,  C.  v. 
Utah;  3,  O.  v.  tularosae;  4,  O.  v.  huckleyi;  5,  O.  v.  couchii; 
6,  C.  V.  rupeatris;  7,  C.  v.  variegatus;  8,  C.  atricapillus. 


J38  NORTH  AMERICAN  FAUNA  [No.  56 

The  subspecies  is  abundant  over  a  large  area  in  south-central 
Mexico.  Specimens  from  Hacienda  La  Parada,  Villar,  and  Rio 
Verde,  in  the  State  of  San  Luis  Potosi,  show  approach  to  couchii  in 
the  darkening  of  the  heads  and  paling  of  the  backs;  their  skulls, 
however,  agree  well  with  those  of  variegatus  and  are  distinctly  larger 
than  those  of  couchii. 

Specimens  examined. — Total  number,  95,  as  follows : 

Colima:  Hacienda  San  Antonio  (at  base  of  Volcano  of  Colima) ,  3. 

Guanajuato:  Santa  Rosa,  2;  Silao,  1. 

Hidalgo:  Encarnacion,  2;  Ixmiquilpan,  2;  Tulancingo,  1;  Zimapan,  1. 

Jalisco:  Ameca,  1;  Atemajac,  9;  Barranca  Ibarra,  1;  Chapala,  1;  Etzatlan,  3; 

Guadalajara,  1 ;  La  Barca,  1 ;  Lagos,  2 ;  Ocotlan,  2 ;  Plantinar,  1 ;  Sierra 

Nevada  de  Colima,  1 ;  Zacoalco,  1 ;  Zapotlau,  6. 
Mexico :  Mount  Popocatapetl,  1 ;  Amecameca,  1 ;  Tlalpam,  6. 
Michoacan :  Acambaro,  1 ;  Los  Reyes,  1 ;  Mount  Tancitaro,  2 ;  Patzcuaro,  12 ; 

Querendaro,  1 ;  Zamora,  2. 
Morelos:  Tetela  del  Volcan,  1. 
Nayarit:  Tepic,  1. 
Puebla:  San  Martin,  1. 
Queretaro:  Tequisquiapan,  1. 
San  Luis  Potosi:  Ahualulco,  1;  Hacienda  La  Parada   (20  miles  northwest  of 

San  Luis  Potosi),  12;  Jesus  Maria,  1;  Rio  Verde,  2;  Villar,  5. 
Zacatecas:  Berriozabal,  1. 

CITELLUS  VARIEGATUS  RUPESTRIS  Allen 

Beown-headed  Rock  Squierel 

(Pis.  26,  C;  31,  C) 

Citellus   (OtospermopliUus)  grammurus  rupestris  Allen,  Amer.  Mus.  Nat.  Hist. 

Bull.  19:  595,  Nov.  12,  1903. 
[Citellus  varieciatus^   rupestris  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.   Ser.  4: 

150,  1904. 
OtospermopliUus    grammurus    rupestris    Miller,    U.    S.    Natl.    Mus.    Bull.    128: 

181,  1924. 

Type. — Collected  on  Rio  Sestin,  northwestern  Durango,  Mexico, 
April  12,  1903,  by  J.  H.  Batty;  female  adult,  skin  and  skull,  no. 
21231,  Amer.  Mus.  Nat.  Hist.  (orig.  no.  419). 

Range. — Eastern  and  western  slopes  of  tlie  Sierra  Madre  and  ad- 
jacent plains  on  eastern  side  from  southern  Durango  north  to  south- 
ern Chihuahua;  east  to  Chihuahua  City  and  Santa  Rosalia;  west  to 
Sierra  de  Choix,  Sinaloa  (fig.  13).  Zonal  range:  Upper  and  Lower 
Sonoran  and  Transition. 

External  characters. — Similar  to  C.  v.  variegatus.,  but  upper  parts 
decidedly  paler  and  brownish  or  buffy  rather  than  blackish  in  tone ; 
head  brown  instead  of  black ;  under  parts  more  buffy ;  similar  also  to 
G.  V.  couchii  but  paler  and  less  blackish  in  general  tone,  and  head 
brown  instead  of  black. 

Cranial  characters. — Skull  similar  to  that  of  variegatus  and  couchii., 
but  averaging  longer  and  relatively  narrower,  with  longer  nasals. 

Color. — (Topotypes  in  April)  :  Top  and  sides  of  head,  nape,  and 
ears,  bone  brown;  front  and  sides  of  face  more  or  less  washed  with 
buffy  white ;  eye  ring  whitish  or  buffy ;  hairs  on  dorsal  area  fuscous  at 
base,  shading  to  bone  brown  on  the  nape  and  to  hair  brown  on  the 
rump  and  sides ;  subterminal  band  of  dorsal  hairs  varying  from  buffy 
white  to  cinnamon  buff ;  tips  of  hairs  brown  or  fuscous ;  tail  above  and 
below,  buffy  white,  mixed  with  fuscous  and  sometimes  also  with 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  139 

light  cinnamon  buff ;  feet  tilleul  buff  or  pinkish  buff,  the  legs  washed 
with  cinnamon  buff  or  ochraceous  tawny ;  under  parts  varying  from 
cinnamon  buff  to  buffy  white. 

Variation. — The  topotype  series  shows  a  large  amount  of  variation 
in  color  in  the  upper  parts,  apparently  due  in  part  to  fading  and  wear 
of  the  pelage.  The  general  tone  of  the  dorsal  surface  varies  from  bone 
brown  to  cartridge  buff  or  cinnamon  buff;  in  a  specimen  from  near 
Guadalupe  y  Calvo,  Chihuahua,  and  one  from  Sierra  de  Choix,  Sin- 
aloa,  the  brown  of  the  head  and  nape  extends  to  or  beyond  the  middle 
of  the  back. 

Molt. — Many  of  the  specimens  from  Eio  Sestin,  taken  in  April,  are 
badly  worn;  two  (Apr.  12,  17)  show  new  pelage  coming  in  on  the 
anterior  half  of  the  back. 

Measurements. — Average  of  9  adult  males  from  tyne  locality  (Allen,  19n3b, 
p.  596)  :  Total  length,  503  (451-540)  ;  tail  vertebrae,  233  (210-^248)  ;  hind  foot 
(without  claws),  56.7  (55.5-57)  ;  ear  from  notch  (dry),  26.3  (25-28).  Fourteen 
adult  females:  Total  length,  499  (463-521)  ;  tail  vertebrae,  227  (203-241)  ;  hind 
foot,  56  (54-60)  ;  ear,  26.3  (25-29).  The  hind  foot,  as  measured  dry  from  7  of 
these  specimens  (5  males;  2  females)  averages  61.1  (59-65).  One  aclult  male 
from  Durango  City:  510;  238;  60;  one  adult  female  from  Guazamota,  Durango : 
548;  263;  60.  ^kull:  Average  of  7  adults  (2  males,  5  females)  from  tvpe  local- 
ity: Greatest  length,  64  (61.2r-67)  ;  palatilar  length,  .30.6  (29-32.5)  ;  zygomatic 
breadth,  38.8  (37.5-40.9)  ;  cranial  breadth,  25.3  (24.6-25.9)  ;  interorbital  breadth, 
15.2  (14.6-16)  ;  postorbital  constriction,  17.2  (15..5-18.1)  ;  length  of  nasals,  23.3 
(22.&-23.7)  ;  maxillary  tooth  row,  12.8  (11.9-13.3). 

Remarks. — This  is  a  well-marked  race,  occupying  an  extensive  area 
in  western  Mexico.  Intergradation  with  C.  v.  grammurus  is  shown 
by  series  from  Chihuahua  and  Santa  Rosalia;  most  of  the  specimens 
from  those  localities  have  the  head  partly  brownish  black  and  agree 
generally  in  color  with  rupestris,  though  two  adults  from  Chi- 
huahua and  three  young  from  Santa  Rosalia  are  scarcely  different 
from  typical  specimens  of  grammurus.  The  skulls  are  likewise  inter- 
mediate in  characters,  resembling  those  of  rupestris  in  shape,  though 
smaller,  and  having  larger  molars  than  grammurus. 

A  single  specimen  from  Guazamota,  southern  Durango,  which 
agrees  in  color  with  riipestns.,  has  a  skull  agreeing  in  size  and  shape 
with  skulls  of  variegatus. 

No  intergrades  of  this  race  with  couchii  have  been  seen,  but  quite 
likely  such  may  be  found  when  collections  are  secured  from  the  terri- 
tory intervening  between  their  known  ranges. 

Specimens  examined — Total  number,  58,  as  follows: 

Chihuahua:  Chihuahua,    9;     Samachique     (Sierra    Tarahumara),    4;"    Santa 

Rosalia,  7;  Sierra  Madre,  near  Guadalupe  y  Calvo,  4. 
Durango:   Coyotes,  3;*^  Durango,  1;   Guazamota,  1;  Rancho  Bailon    (east  of 

Sestin  Valley),  10;"  Rio  Sestin,  17. 
Sinaloa:  Sierra  de  Choix  (50  miles  northeast  of  Choix),  1. 
Sonora:  Oposura,  1. 

CITELLUS  VARIEGATUS  COUCHII    (Baird) 

Couch's  Rock  Squirrel 

SpermopJiilus  couchii  Baird,  Acad.  Nat.  Sci.  Phila.  Proc.  1855 :  332. 
S[permophilus]  grammurus  couchii  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  8:  68,  1896 

^^Amer.  Mus.  Nat.  Hist. 
*i  Field  Mus.  Nat.  Hist. 


140  NORTH  AMERICAN  FAUNA  [No.  56 

Citellus  variegatus  couchi  Bailey,  North  Amer.  Fauna  25 :  83,  1905. 
OtospermopMlus  grammurus  couchii  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  324, 1907. 

Type. — Collected  at  Santa  Catarina  (a  few  miles  west  of  Mon- 
terey) ,  Nuevo  Leon,  Mexico,  April  1853,  by  Lt.  D.  N.  Couch;  skin  and 
skull,  no.  i3^  U.  S.  Natl.  Mus. 

Range. — Northeastern  Mexico,  from  southern  Coahuila  and  Nuevo 
Leon  north  to  the  Chisos  Mountains,  Tex.  (fig.  13).  Zonal  range: 
Upper  and  Lower  Sonoran. 

External  characters. — Similar  to  G.  v.  variegatus  but  smaller ;  dor- 
sum paler  and  more  brownish  or  buffy  (less  blackish);  feet  paler; 
top  of  head  always  black  or  dark  brown.  Similar  to  G.  v.  rupestris 
but  head  and  upper  parts  darker  and  more  blackish  (less  brownish  or 
buffy) ;  under  parts  darker. 

Granial  characters. — Skull  similar  to  that  of  variegatus  but  aver- 
aging smaller,  especially  in  the  males. 

Golor. — (Specimens  in  normal  phase  from  Saltillo,  Coahuila) : 
Front  and  sides  of  face  grayish,  with  a  tinge  of  brown ;  crown,  occi- 
put, sides  of  head,  and  ears,  dark  seal  brown  or  black ;  eyelids  broadly 
margined  above  and  below  with  grayish  white;  hairs  on  dorsal  area 
fuscous  at  base,  tipped  with  white  on  nape  and  shoulders,  and  with 
pinkish  buff  on  middle  and  hinder  back ;  middle  of  back  often  show- 
ing a  brownish  patch. 

Variation. — Of  eight  specimens  collected  at  the  type  locality,  only 
one  is  of  the  normal  color,  the  other  seven  being  melanistic ;  in  these 
the  head  and  upper  parts  are  dark  blackish  brown,  shading  on  hinder 
back  to  dark  seal  brown;  feet  and  under  parts  seal  brown;  tail  seal 
brown,  shaded  with  blackish  brown.  In  faded  pelage  these  melanistic 
specimens  show  patches  of  cinnamon  or  walnut  brown  on  the  back. 

Molt. — Specimens  taken  at  the  type  locality  on  April  13  show  the 
molt  in  progress,  the  greater  part  of  the  body  having  acquired  a  new 
coat,  while  patches  of  the  old  faded  pelage  still  remain  on  the  rump 
and  hinder  back. 

Measurements. — ^Average  of  15  adults  (9  males,  6  females)  from  Santa  Cata- 
rina and  Saltillo,  Mexico:  Total  length,  466  (430-493);  tail  vertebrae,  204 
(174-235)  ;  hind  foot,  60.9  (58-64).  Skull:  Average  of  16  adults  (8  males,  8 
females)  from  the  same  localities:  Greatest  length,  60.1  (57-63.6);  palatilar 
length,  28.6  (26-30.5)  ;  zygomatic  breadth,  37.4  (34-39.3)  ;  cranial  breadth,  24.7 
(23.5r-25.5)  ;  interorbital  breadth,  15  (12.3-17.4)  ;  postorbital  constriction,  17 
(15.9-18.1)  ;  length  of  nasals,  20.4  (18.5-21.9)  ;  maxillary  tooth  row,  12.4 
(11.8-13). 

Remarks. — This  race  is  closely  related  to  variegatus  and  furnishes 
a  link  connecting  the  latter  with  G.  v.  grammurus.  In  the  typical 
form,  as  found  in  Coahuila  and  Nuevo  Leon,  it  is  distinguished  by 
the  combination  of  a  blackish  or  brownish  head,  sharply  contrasted 
with  a  rather  pale-colored  back. 

Writing  of  these  squirrels  as  seen  at  Santa  Catarina,  Nuevo  Leon, 
Nelson  (ms,  notes)  says: 

Although  the  bare  sun-baked  limestone  slopes  of  the  canyons  where  they 
live  are  practically  devoid  of  any  cover  formed  by  vegetation  and  the  rocks 
are  pale  gray,  so  that  these  animals  live  in  a  glare  of  intense  light,  yet  at 
least  80  percent  of  those  seen  were  melanistic.  These  black  animals  sunning 
themselves  on  the  pale-colored  rocks  were  very  conspicuous. 

At  Saltillo,  Coahuila,  where  12  specimens  were  taken,  no  black 
ones  were  seen,  but  in  the  canyons  of  the  Sierra  Guadalupe  more  than 
half  of  the  animals  seen  were  in  the  melanistic  phase. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  141 

Four  specimens  from  the  Chisos  Mountains,  Tex.,  are  best  referred 
to  this  race,  although  two  of  them  show  apparent  intergradation 
with  grammurus  in  ha\dng  the  heads  partly  gray  rather  than  solid 
black ;  one  of  the  black-headed  ones  has  the  black  color  reaching  to 
the  middle  of  the  back,  as  in  C.  v.  huckleyi.  The  skulls  agree  closely 
with  those  of  typical  G.  v.  couchii.  One  specimen  from  Boquillas, 
Tex.,  in  the  melanistic  phase  is  wholly  seal  brown. 

Specimens  examined. — Total  number,  29,  as  follows : 

Coahuila:  Carneros,  1;  Saltillo,  12;  Sierra  Encarnacion,  1;  Sierra  Guadalupe.  1. 

Nuevo  Leon:  Santa  Catarina,  8. 

Tamaulipas:  Victoria,  1. 

Texas :  Boquillas,  1 ;  Chisos  Mountains,  4. 

CITELLUS  VARIEGATUS  BUCKLEYI    (Sr^vcK) 

Blvck-backed  Rock  Squikbei. 

(PI.  7) 

Spermophilus  ImckJeyi  Slack,  Acad.  Nat.  Sci.  Phila.  Proc.  1861:  314. 
Spermophilus  grammurus  buckleyi  Allen,  Amer.  Mus.  Nat  Hist.   Bull.   8:  67, 

1896. 
Citellus  variegatus  "buckleyi  Bailey,  North  Amer.  Fauna  25:  84,  1905. 
Otospermophilua  grammurus  buckleyi  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  323, 

1907. 

Type. — Collected  at  Packsaddle  Mountain,  Llano  County,  Tex., 
about  1861  by  S.  R.  Buckley ;  entered  as  no.  998,  Museum  Acad.  Nat. 
Sci.,  Philadelphia,  but  now  reported  missing. 

Range. — South-central  Texas,  "in  the  rough  and  semiarid  mesquite 
country  along  the  eastern  slope  of  the  southern  arm  of  the  Staked 
Plains'  (Bailey,  1905,  p.  84),  from  the  upper  Nueces  River  (Rock- 
springs)  east  nearly  to  San  Antonio  and  Austin;  north  to  San  Saba 
River  (fig.  13).    Zonal  range:  Upper  and  Lower  Sonoran. 

External  characters. — Similar  to  C.  v.  couchii  but  upper  parts  more 
extensively  blackish. 

Cranial  characters. — Skull  similar  to  that  of  couchii^  but  averaging 
larger,  with  longer  nasals;  shorter  and  relatively  broader  than  that 
of  C.  V.  rupestris,  with  smaller  molariform  teeth. 

Color. — Head  and  anterior  upper  parts,  to  or  beyond  the  middle 
of  the  back,  black  or  dark  seal  brown,  sometimes  sparingly  sprinkled 
with  whitish  hairs,  especially  along  the  sides ;  hinder  back  and  sides 
grizzled  iron  gray,  the  bases  of  the  hairs  fuscous,  tipped  with  white 
or  pale  buff ;  feet  drab  gray,  more  or  less  washed  with  fuscous ;  tail 
fuscous  black,  variegated  and  tipped  with  pale  buffy  white ;  under 
parts  fuscous,  more  or  less  shaded  with  white  and  pinkish  buff. 

Variation. — Wholly  black  individuals  of  this  race  have  not  been 
seen;  one  from  Japonica,  Tex.,  however,  has  the  black  extending 
along  the  back  from  nose  to  root  of  tail  with  a  considerable  mixture 
of  whitish  hairs  along  the  sides;  a  juvenile  specimen  from  Llano 
has  the  crown  black,  but  the  rest  of  the  body  grizzled  gray. 

Molt. — Two  specimens  from  Llano,  taken  May  12  and  13,  sliow 
the  molt  in  progress,  fresh  pelage  covering  the  anterior  part  of  the 
body  to  beyond  the  middle  of  the  back.  One  from  Japonica,  taken 
July  7,  shows  fresh  pelage  covering  nearly  the  whole  body  except  a 
small  strip  across  the  middle  of  the  back,  where  the  old  faded  pelage 
still  remains. 


142  NORTH  AMERICAN  FAUNA  [No.  56 

Measurements. — Average  of  11  adults  (5  males,  6  females)  from  central 
Texas  (Llano,  Japonica,  Rocksprlngs,  Camp  Verde)  :  Total  length,  500  (470- 
525)  ;  tail  vertebrae,  226  (210-252)  ;  hind  foot,  62  (60-65)  ;  ear  from  notch 
(dry),  19.7  (19-22).  SJadl:  Average  of  15  adults  (6  males,  9  females),  from 
Mason  and  Llano,  Tex.:  Greatest  length,  62.9  (60.6-64.8);  palatilar  length. 
29.8  (28.5-31)  ;  zygomatic  breadth,  38.3  (36.4-40.2)  ;  cranial  breadth,  25.1  (24.7- 
26.3)  ;  interorbital  breadth,  14.5  (13.7-15.9)  ;  postorbital  constriction,  17.7 
(16.5-18.4)  ;  length  of  nasals,  23.6  (21.5-24.8)  ;  maxillary  tooth  rovp,  12.2 
(11.5-13). 

Remarks. — This  race  occupies  a  small  area  at  the  eastern  edge  of 
the  range  of  the  species  in  Texas;  it  has  developed  large  size  and 
extensively  blackish  coloration.  Apparently  it  intergrades  with  G.  v. 
grammuriis  in  the  region  between  the  mouths  of  Pecos  and  Devils 
Rivers,  the  specimens  from  that  section  being  referred  to  grammurus. 
Bailey  (1905,  p.  84),  however,  states: 

Apparently  the  open  divide  between  the  headwaters  of  the  Nueces  and  the 
headwaters  of  the  streams  flowing  into  the  Rio  Grande  separates  the  ranges  of 
buckJeyl  and  coiichi  [here  referred  to  grammurus]  with  a  neutral  strip  in 
which  neither  occurs. 

He  adds  (ms.  notes)  : 

I  see  no  way  to  account  for  the  peculiar  coloration  of  this  squirrel  on  the 
grounds  of  protective  coloration.  There  are  few  if  any  dark  colored  rocks  or 
burnt  logs  and  trees  [in  its  habitat].  The  rocks  are  mainly  light  colored 
granite. 

Specimens  examined. — Total  number,  42,  as  follows: 

Texas:  Austin  (16  miles  northwest),  1;  Bull  Creek  (Travis  County),  1; 
Camp  Verde  (7  miles  west,  Kerr  County),  3;  Fort  Mason,  1;  Ingram  (Kerr 
County),  3;*"  Japonica  (Kerr  County),  1;  Llano,  11;  Mason,  18;  Rock- 
springs,  3. 

CITELLUS  VARIEGATUS  GRAMMURUS   (Say) 
Say's  Rock  Squierel 

Siciurusi  f/rammurus  Say,  Long's  Exped.  Rocky  Mountains  2:  72,  1823. 

[Spermophilus  grammurus^  var.  grammurus  Allen.  Boston  Soc.  Nat.  Hist.  Proc. 
16:  293,  1874. 

Anisonyx  {Otospermophilus)  grammurus  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  7: 
237,  1895. 

[Citellus  variegattis]  grammurus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  4: 
149,  1904. 

Otospermophilus  grammurus  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  315,  1907. 

Citellus  grammurus  grammurus  Miller,  U.  S.  Natl.  Mus.  Bull.  79:  208,  1912. 

Citellus  variegatus  juglans  Bailey,  Biol.  Soc.  Wash.  Proc.  26:  131,  1913  (Glen- 
wood,  N.  Mex.). 

Otospermophilus  grammurus  grammurus  Miller,  U.  S.  Natl.  Mus.  Bull.  128:  180, 
1924. 

Type. — None  designated ;  specimen  on  which  Say's  description  was 
based  was  taken  on  Purgatory  River,  near  mouth  of  Chacuaco  Creek, 
Las  Animas  County,  Colo.  (Cary  1911,  p.  87). 

Range. — Mountain  valleys  and  foothills  in  Colorado,  New  Mexico, 
Arizona,  southeastern  and  southwestern  Utah,  southern  Nevada, 
northwestern  Chihuahua,  and  eastern  Sonora ;  north  to  eastern  Lari- 
mer County,  Colo,;  east  to  Baca  County,  Colo.;  south  to  southern 
Texas  (Eagle  Pass),  and  southern  Sonora;  west  to  the  Providence 
Mountains,  Calif.,  and  Charleston  Mountains,  Nev.  (fig.  13).    Zonal 

*2  Cleveland  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  143 

'lange:  Upper  Sonoran  and  Transition  (4,200-8,500  feet  in  New 
Mexico). 

External  characters. — Similar  to  C.  v.  couchii  but  much  paler,  and 
head  without  any  black. 

Cranial  characters. — Skull  very  similar  to  that  of  couchii  but 
averaging  slightly  shorter,  though  of  the  same  breadth ;  nasals  longer, 
projecting  slightly  beyond  the  posterior  ends  of  the  premaxillae; 
niolariform  teeth  smaller. 

Color. —  (April  specimen  in  unworn  pelage,  18  miles  south  of 
La  Junta,  Colo.)  :  Head  and  occiput  pinkish  buff,  faintly  shaded  with 
fuscous;  sides  of  nose  cartridge  buff;  ej^e  ring  white;  fore  part  of 
back,  shoulders,  and  sides  grayish  white,  slightly  mixed  with  brown- 
ish ;  hinder  part  of  back  and  rump  cinnamon  buff,  moderately  varied 
with  clove  brown;  bases  of  hairs  on  dorsal  area  clove  brown;  ears 
hair  brown,  shaded  with  pinkish  buff;  front  legs  buffy  white;  hind 
legs  cinnamon  buff;  fore  and  hind  feet  cartridge  buff;  tail  mixed 
pinkish  buff  and  bone  brown,  edged  with  grayish  white;  under  parts 
buffy  white,  shaded  with  pinkish  buff. 

Variation. — September  specimens  from  Bear  Canyon,  N,  Mex., 
(about  12  miles  northeast  of  Raton)  and  others  from  various  parts  of 
the  range  of  the  subspecies  are  considerably  darker  than  the  April 
specimens  described  above ;  the  middle  and  hinder  back  pinkish  cinna- 
mon, heavily  washed  with  brown  (the  general  tone  about  cinnamon 
brown)  ;  head  pinkish  cinnamon  more  or  less  shaded  with  brown ; 
sides  of  nose  pinkish  buff;  ears  clove  brown  outside,  wood  brown  in- 
side; feet  pinkisli  buff  or  cinnamon  buff;  tail  mixed  black  and  buffy 
white;  edged  with  grayish  white.  Occasional  specimens  (Fort  Hua- 
chuca  and  Graham  Mountains,  Ariz.)  have  the  back  clear  grayish, 
with  only  a  very  slight  wash  of  buff. 

Molt. — There  is  normally  but  one  molt  annually,  in  July  or  August. 
Two  specimens  (male  and  female)  taken  at  San  Pedro,  N.  Mex.,  July 
5  and  6,  show  new  pelage  covering  the  anterior  half  of  the  body,  the 
posterior  half  being  badly  worn.  An  adult  female  from  Big  Sandy 
Creek.  Ariz.,  July  21,  shows  a  similar  progress  of  the  molt.  An  adult 
male  from  Sierra  Grande,  N.  Mex.,  August  19,  is  molting  irregularly 
on  the  dorsal  surface.  An  adult  female  from  Red  Lake,  Ariz.,  Sep- 
tember 7,  is  badly  worn  on  the  anterior  half  of  the  body  and  has  the 
posterior  portion  covered  with  a  fresh,  full  pelage. 

As  the  season  advances  the  pelage  usually  becomes  paler  and  more 
grayish,  due  apparently  to  wearing  off  of  the  buffy  tips  to  the  hairs 
of  the  dorsal  area. 

Measurements. — Average  of  11  adults  (3  males,  8  females)  from  southeastern 
Colorado  (La  Junta,  Trinidad,  Canon  City)  :  Total  length,  467.7  (434-510)  ; 
tail  vertebrae,  210.3  (19S-235)  ;  hind  foot,  57  (53-GO)  ;  ear  from  notch  (dry),  17 
(15-19)  ;  average  of  10  adults  (4  males,  6  females)  from  southeastern  Arizona 
(Fort  Huachuca,  Oracle,  Santa  Catalina  Mountains):  477;  204;  58;  19.5. 
Skull:  Average  of  6  adult  males  from  northeastern  New  Mexico  (Polsom,  Chico 
Springs,  Sierra  Grande)  and  Trinidad,  Colo.:  Greatest  length,  G0.9  (58.8-63.5)  ; 
palatilar  length,  29.3  (28.5-30);  zvgomntic  breadth,  37.9  (30.4-39.1);  cranial 
breadth,  25  (24.1-25.7)  ;  interorbital  breadth,  14.S  (13.5-15.8)  ;  postorbital  con- 
striction, 17.6  (16.8-18.6)  ;  length  of  nasals,  21.9  (20.6-23)  ;  maxillary  tooth  row, 
11.7  (11.3-12).  Average  of  10  adult  females  from  southeastern  Colorado  (Trini- 
dad, La  .lunta.  Canon  City)  and  northeastern  New  Mexico  (Clayton,  Bear  Can- 
yon) :  Greatest  length,  59.7  (57.8-62.7)  ;  palatilar  length,  28.5  (26.8-29.7)  ;  zygo- 
matic breadth,  36.6  (34-38.9)  ;  cranial  breadth,  24.9  (24.1-25.6)  ;  interorbital 
breadth,  14.7    (13.5-15.6);  postorbital  constriction,  17.4    (16.2-18.2);   length  of 


l^  NORTH  AMERICAN  FAUNA  [No.  56 

nasals,  21.1  (20-22.3);  maxillary  tooth  row,  11.8  (11.3-12.3).  Average  of  12 
adult  females  from  Fort  Huachuca,  Ariz.:  60.5;  29.2;  37.1;  25.3;  14.8;  18; 
21.8;  11.8. 

Remarks. — Say's  rock  squirrel  has  a  very  wide  range  and  is  sub- 
ject to  great  individual  and  seasonal  variation.  No  appreciable 
departure  from  the  typical  coloration  is  found  in  the  large  series 
examined  from  New  Mexico  and  Arizona,  including  the  form  ^^jug- 
lans"  named  by  Bailey  from  Glenwood,  N.  Mex. 

A  series  of  10  specimens  from  the  Davis  Mountains,  Tex.,  shows 
approach  to  couchii  in  the  darkening  of  the  heads  of  about  half  of 
the  series;  only  one  individual,  however,  has  a  wholly  black  head. 
The  skulls  average  somewhat  larger  than  those  of  either  grammurus 
or  couchii^  being  in  fact,  about  the  size  of  those  of  O.  v.  tuehleyi. 

A  series  of  15  specimens  from  the  Rio  Grande,  between  the  Pecos 
River  and  Devils  River,  shows  intergradation  with  liucMeyi  in  par- 
tial darkening  of  the  heads  and  shoulders  of  5  individuals,  the  ma- 
jority being  almost  typical  of  grammurus.  Skulls  of  two  of  the 
specimens  are  larger  even  than  those  of  huokleyi^  while  those  of  three 
other  adults  are  typical  of  grammurus. 

Specimens  from  Colonia  Garcia,  Chihuahua,  and  from  numerous 
localities  in  Sonora  as  far  south  as  Camoa,  on  the  Rio  Mayo,  are 
only  slightly  darker  than  typical  grammurus.  One  from  Oposura 
and  one  from  Ortiz,  however,  have  considerable  black  on  the  nape 
and  shoulders,  thus  showing  approach  to  G.  v.  rupestris;  the  skulls 
of  all  of  these  from  Chihuahua  and  Sonora  agree  closely  with  typ- 
ical grammurus  and  do  not  approach  rupestris  in  any  characters. 

This  race  intergrades  with  the  subspecies  utah  in  southwestern 
and  probably  in  eastern  Utah;  the  few  specimens  examined  from 
western  Colorado  appear  to  be  typical  grammurus. 

There  is  no  indication  that  this  species  intergrades  with  heecheyi, 
specimens  from  the  Providence  Mountains,  Calif.,  being  typical 
grammurus. 

Specimens  examined. — Total  number,  437,  as  follows : 

Arizona:  Anderson  Mesa  (Coconino  County),  1;  Apache  (Cochise  County),  2; 
Apache  Maid  Mountain  (Coconino  County),  2;  Baker  Butte  (Coconino 
County),  2;  Bates  Well  (20  miles  south  of  Ajo,  Pima  County),  1;  Beale 
Spring  (near  Kingman,  Mohave  County),  1;  Big  Sandy  Creek  (near  Owens, 
Mohave  County),  2;  Bill  WUliams  Mountain,  1;  Bisbee,  1;  Black  River 
(5  miles  above  mouth  of  White  River),  1;  Blue  River  (Cosper  Ranch, 
Greenlee  County),  3;  Calabasas  (Santa  Cruz  County),  4;  Chiricahua 
Ranch  (San  Carlos  Indian  Reservation,  Graham  County),  1;  Chiricahua 
Mountains,  2;  Crown  King  (Yavapai  County),  1;  Congress  Junction 
(Yavapai  County),  1;  Camp  Verde  (Yavapai  County),  2;  Dos  Cabezos 
(Cochise  County),  1;  Fish  Creek  (Tonto  National  Forest,  Maricopa 
County),  1;  Fort  Bowie  (Cochise  County),  2;  Fort  Grant  (Graham 
County),  3;  Fort  Huachuca,  30;  Fort  Lowell,  1;  Fort  Whipple  (Yavapai 
County),  1;  Galiuro  Mountains  (Graham  County),  1;  Graham  Mountains, 
12;  Grand  Canyon  (Coconino  Plateau),  8;  Huachuca  Mountains,  12; 
Hualpai  Mountains,  9;  Keams  Canyon  (Navajo  County),  1;  Kingman,  1;'^ 
Kirkland  (Yavapai  County),  1;  La  Osa  (Pima  County),  1;  Mayer  (Ya- 
vapai County),  2;  Mineral  Park  (Mohave  County),  2;  Montezuma  Well 
(near  Camp  Verde,  Yavapai  County),  4;  Mowry  (Patagonia  Mountains), 
1;  Nantan  Plateau  (San  Carlos  Indian  Reservation),  3;  Nogales,  2; 
Oatman,  1;"  Oracle  (Pinal  County),  15;  Oak  Creek  (15  miles  southwest 
of  Flagstaff),  2;  Patagonia  Mountains,  5;  Payson  (Gila  County),  1; 
Phantom  Ranch  (Grand  Canj^on),  2;  Pine  Spring  (8  miles  north,  Hualpai 

*'  Univ.  Michigan  Mus.  Zool. 
«  Cleveland  Mus.  Nat.  Hist. 


19381  REVISION  OF  THE  GROUND  SQUIRRELS  145 

Indian  Reservation),  1;  Portal  (Cochise  County),  2;  Prescott,  3;  Prieto 
Plateau  (east  fork  Eagle  Creek,  Greenlee  County),  1;  Red  Lake  (Coconino 
County),  2;  Rice  (Gila  County),  1;  Roosevelt  (Gila  County),  2;  San 
Bernardino  Ranch  (Mexican  boundary),  2;  San  Francisco  Mountain,  3; 
Santa  Cataliua  Mountains,  2;  Santa  Cruz  River  (near  Monument  118), 
2 ;  Santa  Rita  Mountains,  3 ;  Sierra  Ancha  Mountains,  2 ;  Simmons 
(Yavapai  County),  1;  Springerville,  2;  Trumbull  Mountains  (Mohave 
County),  5;  Tubac,  1;  Tucson  Mountains,  1;  Vicksburg  (Yuma  County), 
1;  Warsaw  Mills  (Pajaritos  Mountains,  near  Monument  132),  4;  White- 
river  (10  miles  north,  Navajo  County),  1. 

California:  Providence  Mountains,  10. 

Chihuahua:  Colonia  Garcia,  5;  San  Luis  Mountains,  4. 

Colorado:  Ashbaugh's  Ranch,  Montezuma  County,  1;  Boulder,  2;  Buena  Vista, 
1 ;  Canon  City,  6 ;  Chaffee  County,  2 ; "  Grand  Junction,  1 ;  La  Junta  (18 
miles  south),  3;  La  Veta,  1;*^  Lyons,  1;  Piuewood  (Larimer  County),  1; 
Plateau  Creek  (12  miles  east  of  Tunnel,  Mesa  County),  1;  Rifle,  1; 
Trinidad,  7. 

Nevada:  Cedar  Basin  (Clark  County),  4;**  Charleston  Mountains,  11;**  Sheep 
Mountains   (Clark  County),  1/^ 

New  Mexico:  Animas  Mountains,  2;  Apache  (Grant  County),  3;  Arroyo  Seco 
(Taos  County),  1;  Bear  Canyon  (5  miles  northeast  of  Bell,  Colfax 
County),  3;  Burro  Mountains  (Grant  County),  3;  Capitan  Mountains,  16; 
Carlsbad,  2;  Carlsbad  Cave,  1;  Carrizozo  (14  miles  north),  1;"  Chico 
(CoLfax  County),  1;  Cienequilla  (10  miles  southwest  of  Taos),  4;  Clayton, 
3;  Cloverdale,  1;  Copperton  (south  of  Mt.  Sedgwick,  Valencia  County), 
1;  Florida  Mountains  (Luna  County),  2;  Folsom,  1;  Fort  Wingate 
(McKinley  County),  1;  Gallup,  1;  Garfield  (Dona  Ana  County),  1;  Gila 
(Grant  County),  1;  Gila  National  Forest  (east  fork  Gila  River),  1;  Glen- 
wood  (Catron  County),  1;  Grant  (Valencia  County),  3;  Guadalupe 
Mountains,  1;  Hachita,  3;  HighroUs  (Otero  County),  4;"  Hondo  Canyon 
(Taos  County),  1;  Hondo  River  (White  Mountains,  Lincoln  County),  1; 
Jicarilla  Mountains,  3;  Lincoln,  2;  Lima  (Catron  County),  1;  Magdalena 
Moimtains,  2;  Manzano  Mountains,  3;  Mescalero,  2;"  Mimbres  Mountains 
(head  of  Rio  Mimbres),  1;  Mosquero  (Harding  County),  2;"  Pecos  (San 
Miguel  County),  1;  Red  River  (8,200  feet  altitude,  Taos  County),  1;  Red- 
rock  (Grant  County),  1;  Riley  (Socorro  County),  2;  Rinconada  (Rio 
Arriba  County),  2;  Rio  Puerco  (Valencia  County),  1;  Ruidoso  (Lincoln 
County),  1;  San  Luis  Mountains,  0;  San  Pedro  (Santa  Fe  County),  3; 
Santa  Rosa,  4;  San  Mateo  Mountains  (Socorro  County),  2;  San  Mateo 
Mountains  (Valencia  County),  1;  Sierra  Grande,  1;  Sweetwater  (15  miles 
southwest  of  Springer),  2;  Tres  Piedras  (Taos  County),  1;  Tularosa,  3; 
Zuni  Mountains  (Valencia  County),  2. 

Sonera:  Bacerac  (15  miles  east),  1;  Camoa,  1;  Cerro  Blanco,  3;^'  Guadalupe 
Canyon  (Monument  73,  Mexican  boundary  line),  2;  Hermosillo,  3;  Mag- 
dalena, 1;  Nogales  (and  32  miles  south),  8;  Ortiz,  1;  Pilares,  1;  Provi- 
dentia  Mines,  4;"  San  Jose  Mountain  (8  miles  south  of  Monument  93, 
Mexican  boundary  line),  3;  Santa  Cruz,  1. 

Texas:  Castle  Mountains  (Cx-ockett  County),  1;  Comstock  (and  40  miles  north- 
west), 2;  Davis  Mountains,  11;  Devils  River,  6;  El  Paso,  1;  Fort  Davis, 
2;  Guadalupe  Mountains,  2;  Langtry,  1;  Painted  Cave  (near  mouth  of 
Pecos  River),  4;  Pecos  High  Bridge,  1. 
Utah:  Beaverdam  Mountains,  1;  Pine  Valley  (Washington  County),  2;  Santa 
Clara,  2. 

CITELLUS   VARIEGATUS  TULAROSAE   Benson 

Malpais  Rock  Squibbel 

Citellus  grammurus  tularosae  Benson,  Calif.  Univ.  Pubs.,  Zool.   Ser.  38:  336, 

Apr.  14,  1932. 
Otospennophilus  grammurus  tularofiae  Bradt,  Jour.  Mammal.  13 :  324,  1932. 

Type. — Collected  at  French's  Ranch,  5,400  feet  altitude,  12  miles 
northwest  of  Carrizozo,  Lincoln  County,  N.  Mex.,  October  28,  1931, 

"  Univ.  Michigan  Mus.  Zool. 
**  Cleveland  ifus.  Nat.  Hist. 

^''D.  R.  Dickey  collection  (California  Inst.  Technology). 
«•  New  Mexico  State  College. 
*''  F'ield  C^olumbian  Mus. 
154970—38 10 


146  '  NORTH  AMERICAN  FAUNA  [No.  56 

by  Seth  B.  Benson;  male  adult,  skin  and  skull,  no.  50935,  Mus.  Vert. 
Zool.  (orig.no.  1603). 

Range. — "Lava  beds  of  the  Tularosa  Basin  in  Lincoln  and  Otero 
Counties,  New  Mexico"  (Benson)  (fig.  13).  Zonal  range:  Lower 
Sonoran. 

External  characters. — ^Very  similar  in  color  to  typical  G.  v.  vaHe- 
gatus.,  but  bead  never  black  and  hinder  back  more  tawny ;  similar  in 
size  to  G.  V.  grammurus  but  coloration  distinctly  darker  (more  black- 
ish), due  largely  to  the  darker  bases  of  the  hairs  on  both  dorsal  and 
ventral  surfaces;  hinder  back  darker  tawny;  hind  feet  slightly 
darker. 

Granidl  characters. — Skull  similar  to  that  of  grammurus  (only  one 
adult  skull  examined;  extent  of  variation  not  known). 

Golor. — ^Winter  pelage  (October)  :  Head  grizzled  with  fuscous  or 
black  and  light  buff ;  eye  ring  white ;  ears  blackish  externally,  edged 
with  buff,  cinnamon  buff  on  inner  surface ;  hairs  on  fore  back  fuscous 
black  basally,  tipped  with  white;  hairs  on  hinder  back  dark  fuscous 
basally,  tipped  with  sayal  brown  and  light  buff;  front  feet  pinkish 
buff,  hind  feet  light  pinkish  cinnamon,  all  more  or  less  grizzled  with 
blackish;  tail  mixed  black  and  grayish  white;  under  parts  grayish 
white  or  pinkish  buff,  the  bases  of  the  hairs  dark  fuscous. 

Measurements. — Adult  male  (type)  :  Total  length,  488;  tail  vertebrae,  206; 
hind  foot,  60;  ear  from  notch  (dry),  18.  SuMdult  female:  437;  172;  53;  17. 
Skull:  Adult  male  (type)  and  subadult  female:  Greatest  length,  63,  57.5;  pala- 
tilar  length,  30,  27;  zygomatic  breadth,  38.6,  34.7;  cranial  breadth,  25.8,  25.1; 
interorbital  breadth,  15.5,  14.7;  postorbital  constriction,  18.3,  17.8;  length  of 
nasals,  23,  20.9;  maxillary  tooth  row,  12.1,  11.8. 

Remarks. — The  Malpais  rock  squirrel,  although  occupying  a  very 
limited  area  in  south-central  New  Mexico,  and  entirely  surrounded  by 
another  wide-ranging  race — grammurus — is  apparently  a  well- 
marked  form.  It  appears  to  be  confined  exclusively  to  the  beds  of 
dark-colored  lava  rock  where  this  and  other  dark  forms  of  rodents 
have  developed. 

Specimens  examined. — Total  number,  4,  as  follows : 

New  Mexico :  French's  Ranch,  12  miles  northwest  of  Carrizozo,  3 ;  ^  Malpais 
Lava  Beds  (near  Carrizozo),  1.** 

CITELLUS  VARIEGATUS  UTAH  Merbiam 

Utah  Rock  Squirrel 

Citellus  grammurus  utah  Merriam,  Biol.  Soe.  Wash.  Proc.  16 :  77,  May  29,  1903. 
Citellus  variegatus  Utah  Elliot,  Field  Columb.  Mus.  Pub.  Zool.  Ser.  6:  115,  1905. 
OtospermopJiilus  grammurus  utah  Miller,  U.  S.  Natl.  Mus.  Bull.  128:  181,  1924. 

Type. — Collected  at  foot  of  Wasatch  Mountains,  near  Ogden,  Utah, 
October  10,  1888,  by  Vernon  Bailey;  female  adult,  skin  and  skull, 
no.  186468,  U.  S.  Natl.  Mus.  (Merriam  collection,  no.  )  (orig.  no. 
291). 

Range. — Central  Utah,  from  the  Wasatch  Range  south  to  the 
Beaver  Mountains;  also  the  Kaibab  Plateau,  Ariz,  (limits  of  range 
imperfectly  known)  (fig.  13).  Zonal  range:  Transition  and  Upper 
Sonoran. 


«Mus.  Vert.  ZooL 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  147 

External  characters. — Similar  to  C.  v.  grammurus^  but  head  and 
posterior  back  darker  (more  tawny),  especially  in  unworn  winter 
pelage. 

Cranial  characters. — Skull  similar  to  that  of  grammuruSs  but  aver- 
aging smaller. 

Color. —  Winter  pelage  (October)  :  Head  mixed  pinkish  buff  and 
fuscous ;  a  broad  buffy  white  eye  ring ;  shoulders  and  fore  back  gray- 
ish white,  the  bases  of  the  hairs  fuscous;  hinder  back  snuff  brown  or 
mikado  brown,  sj)aringl3^  tipped  with  light  buff ;  lower  sides  grayish 
white;  feet  pinkish  buff  or  grayish  buff;  tail  mixed  pale  buff  and 
fuscous  black ;  under  parts  buffy  white  or  pale  pinkish  buff'. 

Molt. — An  adult  female  (nursing)  taken  at  Nephi,  Utah,  July  5, 
is  in  worn  winter  pelage  and  shows  new  pelage  coming  in  on  the 
head  and  nape. 

Measurements. — Average  of  7  adult  males  from  Utah  (Ogden,  Salt  Lake  City, 
Provo)  :  Total  length,  467  (454-495)  ;  tail  vertebrae,  IDS  (185-210)  ;  hind  foot, 
G0.5  (59-63)  ;  ear  from  notch  (dry),  19.5  (18.5-21).  Average  of  5  adult  fe- 
males from  Utah  (Ogden,  Provo,  Salt  Lake  City,  Marysvale)  :  Total  length,  438 
(425-460);  tail  vertebrae,  189  (180-199):  hind  foot,  58.8  (56-61);  ear  from 
notch  (dry),  18.7  (18-19).  Skull:  Average  of  4  adult  males  from  Utah  (Ogden, 
Provo,  Salt  Lake  City)  :  Greate.st  length,  60.3  (57.5-63)  ;  palatilar  length,  29.2 
(28-30.5)  ;  zygomatic  breadth,  36.9  (35.5-38)  ;  cranial  breadth,  25.3  (24.8-2-5.8)  ; 
interorbital  breadth,  14.7  (14.2-15.2)  ;  postorbital  constriction,  17.5  (17.1-18.3)  ; 
length  of  nasals,  21.1  (19.8-22.4);  maxillary  tooth  row,  11.5  (11.4-12).  Aver- 
age of  6  adult  females  from  same  localities:  Gi'eatest  length,  57.9  (5(>-59.5)  ; 
palatilar  length,  27.7  (27-28.5)  ;  zygomatic  breadth,  35.6  (34.6-36.8)  ;  cranial 
breadth,  24.1  (23.5-24.6)  ;  interorbital  breadth,  13.5  (13.2-14.3)  ;  postorbital 
constriction,  16.9  (16-17.5)  ;  length  of  nasals,  20.6  (18.9-21.9)  ;  maxillary  tooth 
row,  11.3  (10.7-11.6). 

Remarks. — The  Utah  rock  squirrel  appears  to  be  a  recognizable 
race,  but  it  is  difficult  to  define  the  limits  of  its  range.  Upon  com- 
parison of  typical  specimens  in  unworn  v.inter  pelage  with  a  similar 
series  of  graramurus  from  southeastern  Colorado — the  type  region — 
marked  differences  in  color  are  noticeable.  However,  throughout  the 
wide  range  of  grammurus  in  New  Mexico  and  Arizona  many  indi- 
vidual specimens  are  found  that  agree  very  closely  in  color  with 
specimens  of  utah.  But  nowhere  in  northern  Utah  do  we  find  speci- 
mens to  match  the  pale  grayish  or  cinnamon  buff  type  occurring  in 
Colorado,  New  Mexico,  and  southeastern  Arizona. 

Two  specimens  from  the  Kaibab  Plateau,  Ariz.,  appear  to  be  refer- 
able to  Utah.,  but  whether  this  race  has  a  continuous  range  from  the 
Beaver  Mountains  south  to  the  Kaibab  is  not  known;  grammurus 
occurs  in  practically  typical  form  in  extreme  southwestern  Utah  and 
southern  Nevada. 

Specimens  examined. — Total  number,  34,  as  follows: 

Arizona:  Big  Spring  (Kaibab  Plateau),  1;  Kaibab  Forest,  l.'^ 

Utah:   Beaver,  1;   Cedar  Fort    (Utah  County),  1;   Florence  Canyon,  35  miles 

north  of  Green  River    (city),  6;°*"  Logan,  3:"^^  Marysvale,  2;   Murray  1; 

Nephi,  1;  Ogden,  8;  Parowan,  1;^^  Provo,  5;  Provo  Canyon,  1;"  Salt  Lake 

City,  2. 


«»Mus.  Vert.  Zool. 

^  Carnegie  Mus. 

WTItah  State.  Agr.  College. 

"^  Cleveland  Mus.  Nat.  Hist. 


148  NORTH  AMERICAN  FAUNA  [No.  56 

CITBLLUS  BEBCHETI  (Richardson) 
[Synonymy  under  subspecies] 

Speci-jh  characters. — Size  small  to  medium ;  hind  foot,  50-63.5  mm ; 
tail,  137-198;  skull  length,  51.6-62.4.    Skull  essentially  similar  to' 
that  of  O.  variegatus  grammurus  except  in  size. 

Color. — Head  varying  from  avellaneous  or  pinkish  cinnamon  to 
wood  brown  or  sayal  brown;  upper  parts  snuff  brown,  wood  brown, 
or  sayal  brown,  flecked  with  buffy  white  or  cinnamon  buff;  sides  of 
neck  and  shoulders  white  or  whitish,  this  color  extending  backward 
as  two  divergent  stripes  to  about  the  middle  of  the  back,  leaving  a 
dark  triangular  area  between ;  under  parts  buff,  of  varying  intensity. 

CITELLUS   BEECHETI  BEECHEYI    (Richakdson) 

CAUFOENIA    GROtrND    SQtriEBEIi 

(PI.  8) 

Arctomys   (Spermophilus)    heecheyi  Richardson,  Fauna  Boreali- American  a   1: 

170,  1829. 
Spermophilus  deecheyi  F.  Cuvier,  Sup.  a  I'hist.  natur.  Buffon  1 :  331,  1831. 
ISpermophilus  prammurus]   var.  beecheyi  Allen,  Boston  Soc.  Nat.  Hist.  Proc. 

16:  293,  1874. 
Citellus  variegatus  beecheyi  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6:  114, 

1905. 
Oto spermophilus  beecheyi  Mearns,  U.  S.  Natl.  Mus.  Bull.  56 :  324,  1907. 
Citellus  grammurus  beecheyi  Miller,  U.  S.  Natl.  Mus.  Bull.  79 :  298,  1912. 
Citellus  beecheyi  beecheyi  Grinnell,  Calif.  Acad.  Sci.  Proc.  (4)  3:  346,  1913. 
Otospermophilus  grammurus  beecheyi  Miller,  U.  S.  Natl.  Mus.  Bull.  128:  180, 

1924. 

Type. — No.  222a,  British  Museum,  skin  with  skull  inside ;  locality 
not  stated;  habitat  given  as  "neighborhood  of  San  Francisco  and 
Monterey,  in  California." 

Range. — ^Western  California,  from  San  Francisco  Bay  south  to 
northern  San  Diego  County;  eastward  through  the  coast  ranges  and 
the  San  Gabriel  Mountains  (fig.  14).  Zonal  range:  Upper  Sonoran 
and  Transition. 

External  characters. — Similar  to  C.  variegatus  grammurus  but 
darker;  white  area  of  the  shoulders  divided  by  a  dark  triangular 
patch  reaching  to  the  crown ;  ears  darker  on  outer  surface.  Sunilar 
to  C.  h.  dougla^ii,  but  slightly  darker;  white  shoulder  patches  less 
extensive,,  and  foreback  without  a  black  patch  between  the  white 
stripes.  In  comparison  with  the  other  races  of  heecheyi,  this  form 
is  darker  (more  brownish)  on  the  head  and  back,  and  more  buffy 
on  the  under  parts. 

Cranial  characters. — Skull  similar  to  that  of  C.  v.  grammurus  but 
smaller  and  relatively  narrower  in  the  postorbital  region;  nasals 
narrower  posteriorly. 

Color. — Fresh  fall  pelage  (San  Mateo  County,  Calif.,  December) : 
Top  of  head  pinkish  cinnamon,  shaded  with  fuscous ;  eye  ring  buffy 
white;  ears  fuscous  black  externally  and  on  the  upper  margin,  pale 
cinnamon  buff  on  inner  surface  and  posterior  outer  margin ;  hairs  of 
upper  parts  fuscous  black  at  base,  tipped  with  pinkish  cinnamon,  the 
general  tone  near  snuff  brown;  sides  of  neck _  and  shoulders  dull 
white,  this  color  extending  backward  as  two  divergent  stripes  that 
fade  out  about  the  middle  of  the  back;  sides  of  body  more  or  less 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


149 


extensively  flecked 
with  dull  white ;  feet 
pale  pinkish  buff ; 
under  parts  pinkish 
buff ;  tail  mixed  black 
and  pinkish  buff. 

Variation.  —  The 
pelage  in  simimer  is 
slightly  paler,  due  to 
wear  and  fading. 

Molt. — The  annual 
molt  occurs  usually 
in  July,  but  may  be 
deferred  imtil  Sep- 
tember. An  adult 
male  from  Marys- 
ville  Buttes,  taken 
July  15,  is  in  much 
worn  pelage  and 
shows  new  pelage 
starting  in  a  small 
area  on  the  fore  back. 
An  adult  female 
taken  on  the  same 
day  at  the  same  place 
is  in  old  worn  pelage 
and  shows  no  indica- 
tion of  molting.  A 
subadult  male  from 
Salinas,  September 
4,  shows  new  pelage 
on  the  head  and  the 
posterior  half  of  the 
body. 

Measuremen  ts. — Aver- 
age of  10  adult  males 
from  type  region  (Berk- 
eley, Walnut  Creek, 
Stanford  University, 
Boulder  Creek,  Monte- 
rey, Mansfield)  :  Total 
length,  434  (410-460)  ; 
tail  vertebrae,  177  (156- 
190)  ;  hind  foot,  HO  (57- 
61 )  ;  ear  from  notch 
(dry),  19.9  (18-21). 
Average  of  10  adult  fe- 
males from  same  sec- 
tion:  Total  length,  401 
(370-442)  ;  tail  verte- 
brae, 158  (137-180)  ; 
hind  foot,  56  (53-59)  ; 
ear  from  notch  (dry), 
20.7    (19-22).      Skull: 

Average  of  20  adult  males  from  Contra  Costa  County:  Greatest  length,  59.4 
(57-62.4)  ;  palatilar  length,  28.8  (27-30.5)  ;  zygomatic  breadth,  38.3  (36.3-40.5)  ; 
cranial  breadth,  24.5  (23.4-25.9)  ;  interorbital  breadth,  14.7  (13.2-15.8)  ;  postorbi- 
tal  constriction,  15.7  (14.8-16.9)  ;  length  of  nasals,  22.1  (20-24)  ;  maxillary  tooth 
row.  12  (11.2-12.9).    Average  of  20  adult  females  from  same  locality:  Greatest 


Figure  14. — Distribution  of  the  subspecies  of  Citellus 
beecheyi:  1,  C.  b.  doiiglasii;  2,  C.  b.  sierrae;  3.  O.  h.  ftsheri; 
4,0.  b.  beecheyi;  5,  C.  b.  parvulus;  6,  C.  b.  nesioticus ; 
7,(7.  b.  nudipes;  8,  C.  b.  rupinarum. 


150  NORTH  AMERICAN  FAUNA  [No.  56 

length,  57.1  (53.9-60.4)  ;  palatilar  length,  27.5  (26^30)  ;  zygomatic  breadth,  36 
(33.6-38.6)  ;  cranial  breadth,  23.6  (22.7-25.2)  ;  interorbital  breadth,  13.8  (12.9- 
15.4)  ;  postorbital  constriction,  15.6  (13.7-16.7)  ;  length  of  nasals,  21  (19.7-22.4)  ; 
maxillary  tooth  row,  11.9  (10.6-12.7). 

RemarJcs. — Any  attempt  to  divide  C.  heecheyi  into  subspecies  is 
certain  to  be  unsatisfactory ;  this  is  because  of  the  large  amount  of 
individual  variation  that  is  found  in  all  races  and  also  because  of 
the  diversified  nature  of  the  country  in  which  the  animals  live.  The 
present  race  is  the  darkest  of  all  the  forms  and  is  typical  only  in  the 
coastal  region  from  San  Francisco  Bay  southward  to  Ventura 
County ;  from  there  southward  the  animals  become  paler  and  smaller, 
grading  into  C.  h.  -fisheri  in  the  Tehachapi  Mountains,  into  G.  h, 
parvulus  in  the  San  Bernardino  Mountains,  and  into  C.  h.  nudipes 
in  the  coastal  region  of  San  Diego  County.  In  many  localities,  the 
variation  in  the  series  is  so  great  that  while  some  of  the  specimens 
are  typical  of  beecheyi,  one  or  more  may  closely  resemble  one  of  the 
other  subspecies. 

Specimens  examined. — Total  number,  197,  as  follows: 

California:  Alhambra,  1;  Aptos  (5  miles  south,  Santa  Cruz  County),  2;  Arroyo 
Seco  (10  miles  south  of  Paraiso  Springs,  Monterey  County),  2;  Arroyo  Seco 
Canyon  (near  Pasadena.  Los  Angeles  County),  3;"  Bear  Basin  (head  of 
Carmel  River,  Monterey  County),  1;  Berkeley,  2;  Bitterwater  (San  Benito 
County),  3;  Boulder  Creek  (Santa  Cruz  County),  3;  Corral  Hollow  (8 
miles  southwest  of  Tracy),  1;^  Contra  Costa  County,  50  (skulls)  \^^  Cor- 
ralitos  (Santa  Cruz  County),  11;  ^  Del  Norte  (7  miles  southeast,  Monterey 
County),  6;  Fremont  Peak  (Gabilan  Range,  Monterey  County),  1;  Gaviota 
Pass  (Santa  Barbara  County),  2;  Half  Moon  Bay,  1;  Hay  ward,  1;  Idria 
Mines  (San  Benito  County),  4;  Jamesburg  (Monterey  County),  1;  Jolon 
(Monterey  County),  1;  Laguna  Ranch  (Gabilan  Range,  San  Benito  County), 
1;  Las  Virgines  Creek  (Los  Angeles  County),  1:  Los  Gatos,  1;  Lytle  Creek 
(San  Bernardino  County),  1;  Mansfield  (Monterey  County),  4;  Monterey, 
6;  Pacific  Grove  (Monterey  County),  1;  Paraiso  Springs  (Monterey  County). 
4;  Paso  Robles,  1;  Pescadero,  1;  Pine  Valley  (head  of  Carmel  River,  Mon- 
terey County),  2;  Posts  (Monterey  County),  1;  Pozo  (San  Luis  Obispo 
County),  3;  Priest  Valley  (Monterey  County),  1;  Redwood  City,  1;  Salinas, 
1;  San  Francisco,  6;  San  Gabriel,  1;  San  Gabriel  Mountains  (Heninger 
Flats),  8;  San  Luis  Obispo,  1;  San  Pedro  (Point  Firmin).  10;  San  Rafael 
Mountains  (Santa  Barbara  County),  1;  San  Simeon  (San  Luis  Obispo 
County),  2;  Santa  Barbara,  3;  Santa  Clara,  1;  Santa  Cruz,  2;  San  Mateo, 
1;  Santa  Inez  Mission  (Santa  Barbara  Comity),  2;  Santa  Monica,  1;  Sea- 
side (Monterey  Coimty),  7;  Sisquoc  (Santa  Barbara  County),  3;  Soledad, 
1;  Stanford  University,  1;  Strawberry  Peak  (San  Gabriel  Mountains),  1; 
Sur  (Monterey  County),  1;  Tassajara  (Contra  Costa  County),  1;  Temescal 
(Riverside  County),  2;  Ventura  River,  1;  Walnut  Creek  (Contra  Costa 
Comity),  5;  "Wilson  Peak  (Los  Angeles  County),  9. 

CITELLUS  BEECHETI  DOUGLASII  Richardson 

Douglas's  Ground  Squirrel 

(Pis.  8;  26,  B;  31,  B) 

Arctomys?    (Spermophihts?)    douglasii  Richardson,   Fauna   Boreali- Americana, 

1 :  172,  1829. 
Spermophilus  douglasii  F.  Cuvier,  Sup.  a  I'hist.  natur.  Buffon  1 :  333,  1831. 
[Spermoplnlus  grammurus']  var.  douglassi  Allen,  Boston  Soc.  Nat.  Hist.  Proc.  16 : 

293,  1874. 
Citellus  V.  douglasi  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3 :  183,  1903. 
Citellus  'beecTieyi  douglasi  Grinnell,  Calif.  Acad.  Sci.  Proc.  (4)  3 :  345,  1913. 


53  Mus.  Vert.  Zool. 

^  Univ.  Michigan  Mus.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  151 

Otospennophilus  grammiints  dotifflasii  Miller,  U.   S.  Natl.  Mns.  Bull.  128:  180, 
1924. 

Type. — None  designated ;  description  based  on  a  hunter's  skin  from 
the  "banks  of  the  Cokimbia"  [River],  sent  to  E-ichardson  by  David 
Douglas. 

Range. — Western  Oregon  and  northern  California,  from  tlie  Colum- 
bia River  Valley  south  nearly  to  San  Francisco  Bay,  Calif.;  east  to 
the  Deschutes  River  Valley,  Oreg. ;  Lake  City,  Calif.,  and  a  line 
reaching  from  the  latter  point  to  Eagle  Lake.  Lyonsville,  Magalia, 
and  Nelson ;  from  there  southward  occurring  only  west  of  the  Sacra- 
mento River  (fig.  14).  Zonal  range:  Mainly  Upper  Sonoran  and 
Transition;  into  Lower  Sonoran  in  the  Sacramento  Valley  and  into 
Canadian  on  the  Siskivou  Mountains  (6,000  feet)  and  the  Scott 
Mountains  (6.800  feet)." 

Exteimal  characters. — Similar  in  general  tone  of  upper  parts  to 
C.  h.  heecheyi^  but  averaging  paler,  especially  on  the  head;  a  large 
triangular  black  patch  on  the  foreback  between  the  white  shoulder 
patches ;  ears  paler ;  under  parts  slightly  paler ;  tail  averaging  longer, 
and  paler  underneath.  Compared  with  C.  h.  fisheri:  Back  darker, 
with  a  black  wedge  between  the  shoulders;  tail  averaging  longer,  and 
deeper  buff  beneath. 

Cranial  characters. — Skulls  of  adult  males  average  larger  than  those 
of  heecheyi  while  skulls  of  females  average  smaller. 

Color. — Fresh  pelage  (October)  :  Nose  and  face  smoke  gray, 
washed  with  pinkish  cinnamon;  crown  mikado  brown  or  cinnamon; 
ears  fuscous  on  outer  surface,  pale  cinnamon  buff  on  inner  surface; 
eye  ring  creamy  white ;  shoulder  patches  pale  smoke  gray,  enclosing  a 
wedge-shaped  patch  of  fuscous  black;  general  tone  of  hinder  back 
near  sayal  brown,  mottled  with  pale  smoke  gray  or  pale  pinkish  buff; 
front  feet  pinkish  buff;  hind  feet  varying  from  cartridge  buff  to  cin- 
namon buff;  tail  above,  mixed  black  and  pale  pinkish  buff,  the  hairs 
edged  with  grayish  white ;  tail  beneath,  cinnamon  buff  or  light  ochra- 
ceous  buff,  more  or  less  obscured  with  grayish  white;  under  parts 
cartridge  buff,  pinkish  buff,  or  grayish  white. 

Variation. — Occasional  specimens  lack  the  black  patch  on  the  back ; 
in  a  series  of  20  specimens  from  The  Dalles,  Oreg.,  one  in  fresh  pelage 
lacks  the  black  patch  entirely  and  four  in  worn  pelage  have  the  black 
nearly  obliterated. 

Molt. — The  annual  molt  takes  place  usually  in  June  or  July,  but 
may  sometimes  be  delayed  till  August  or  early  September,  Certain 
individuals  in  spring  and  early  summer  become  greatly  worn  before 
molting,  so  that  the  blackish  patch  on  the  fore  back  becomes  faded  or 
nearly  obliterated. 

Specimens  taken  at  The  Dalles,  Oreg.,  June  10,  show  new  pelage 
coming  in  on  the  head  and  fore  back;  female  specimens  from  Still- 
water, Calif.,  July  1,  and  Drew,  Oreg.  July  28,  are  in  similar  condi- 
tion of  pelage;  nursing  females  from  Forest  (jrove,  Oreg.,  July  16, 
and  Tower  House,  Calif.,  August  4,  are  in  badly  worn  pelage  and  had 
not  started  to  molt ;  another  nursing  female,  from  Chico,  Calif.,  Sep- 
tember 19,  had  just  acquired  a  fresh  pelage  over  the  anterior  half  of 
the  back,  the  hinder  back  being  in  worn  and  faded  pelage. 

Measurements. — Averago  of  10  adult  males  from  Oregon:  Total  length,  476 
(450-500)  ;  tail  vertebrae,  207  (190-223)  ;  hind  foot,  61  (56-6Li)  ;  ear  from  notch 


1 52  NORTH  AMERICAN  FAUNA  [No.  56 

(dry),  19.5  (17.5-22).  Average  of  10  adult  females  from  Oregon:  Total  length, 
450  (440-460)  ;  tail  vertebrae,  193  (182-200)  ;  hind  foot,  58.6  (57-60)  ;  ear  from 
notch  (dry),  18.4  (17-20).  Skull:  Average  of  8  adult  males  from  Oregon:  Great- 
est length,  61.5  (59.2-63.2)  ;  palatilar  length,  30.1  (29.2-31)  ;  zygomatic  breadth, 
38.1  (36.3-39.9)  ;  cranial  breadth,  24.5  (24-25)  ;  interorbital  breadth,  14.2  (13.3- 
15.7)  ;  postorbital  constriction,  15.1  (14.5-15.8)  ;  length  of  nasals,  22  (20.5-23.5)  ; 
maxillary  tooth  row,  11.5  (11.1-12).  Average  of  10  adult  females  from  The 
Dalles,  Oreg. :  Greatest  length,  56.1  (54.6-57.8)  ;  palatilar  length,  26.9  (26-27.8)  ; 
zygomatic  breadth,  34.1  (33.2-35.3)  ;  cranial  breadth,  23.1  (22-24)  ;  interorbital 
breadth,  12.8  (11.5-13.4)  ;  postorbital  constriction,  15.8  (14.9-16.9)  ;  length  of 
nasals,  19.3  (18.5-20.6)  ;  maxillary  tooth  row,  10.8  (10.1-11.2). 

Remarks. — Douglas's  ground  squirrel  is  closely  related  to 
beecheyi,  differing  chiefly  in  having  a  large  black  patch  on  the  fore- 
back  between  the  whitish  side  stripes;  the  range  of  douglasii  is 
separated  from  that  of  fisheri  by  the  Sacramento  River  for  a  con- 
siderable distance  in  central  California,  but  in  the  vicinity  of  Chico, 
douglasii  crosses  to  the  east  side  of  the  river  and  meets  the  range  of 
■fisheri  in  Butte  County.  Typical  specimens  of  douglasii  have  been 
collected  at  points  nine  miles  east  of  Chico  and  eight  miles  east  of 
Nelson.  At  Oroville  and  Yankee  Hill  typical  fisheri  occurs,  while  at 
Cherokee  and  Pentz  typical  specimens  of  each  and  some  with  inter- 
mediate characters  have  been  taken.  This  condition  suggests  hybrid- 
ization rather  than  the  usual  type  of  intergradation,  but  in  considera- 
tion of  the  close  resemblance  between  the  two  forms  in  color  and 
with  no  important  difference  between  them  in  skull  characters,  it 
seems  best  to  treat  them  as  subspecies. 

The  present  species  is  reported  to  have  crossed  the  Columbia  River 
and  established  itself  near  White  Sahnon,  Wash.,  within  very  re- 
cent times.  In  July  1917,  W.  N.  Suksdorft  stated  that  it  had  come 
in  within  the  past  2  or  3  years  and  had  already  spread  for  2  or  3 
miles  up  the  river  valley. 

Specimens  examined. — Total  number,  338,  as  follows: 

California:  Adin  (Modoc  County),  7;  Bald  Mountain  (8  miles  south,  Shasta 
County),  2;  Balls  Ferry  (Shasta  County),  1;"  Bartlett  Mountain  (Lake 
County),  2;  Bear  Creek  Valley  (Shasta  County),  1;  Beswick  (Siskiyou 
County),  6;  Bieber  (Lassen  County),  1;  Branscomb  (Mendocino  County), 
1;°*  Burney  (Shasta  County),  4;  Cahto  (Mendocino  County),  1;  Calpella 
(Mendocino  Comity),  1;  Cassell  (Shasta  County),  5;  Cherokee  (Butte 
County),  2;'°  Chico,  17;  Cloverdale,  3;  Dana  (Shasta  County),  3;  Davis, 
1;  Dry  Creek  (Butte  County),  4;"  Eagle  Lake  (Lassen  County),  2;  Eel 
River  (Humboldt  County),  6;  Elmira  (Solano  County),  1;  Eureka,  3;" 
Fairfield,  6;  Fall  River  Mills,  1;  Fort  Crook  (Shasta  County),  6;  Glen 
Ellen  (Sonoma  County),  13;  Goose  Lake,  3;  Guenoc  (Lake  County),  1; 
Hayden  Hill  (Lassen  County),  4;  Healdsburg,  1;  Hoopa  Valley  (Huml)oldt 
County),  7;  Hornbrook,  3;  Mad  River  (Carson's  Camp,  Humboldt  Bay),  2; 
Lake  Cit.v  (Modoc  County),  1;  Lakeport,  1;  Lower  Lake  (Lake  County), 
3;  Lyonsville  (Tehama  County),  2;  Magalia  (Butte  County),  1;  Merrill- 
ville  (Lassen  County),  1;  Middletown  (Lake  County),  1;  Mill  Creek  (east 
of  Lyonsville,  Tehama  County),  1;  Montague,  1;  Mount  George  (Napa 
County),  1;  Mount  St.  Helena  (Sonoma  County),  2;  Mount  Veeder  (10 
miles  N.  W.  of  Napa),  2;  Nelson  (Butte  County),  2;  North  Yolla  Bolly 
Mountain  (12  miles  north.  Trinity  County),  1;°°  Paynes  Creek  (Tehama 
County),  1;  Pentz  (Butte  County),  4;°'  Petaluma,  3;  Pittville  (Shasta 
County),  1;  Red  Bluff,  11;  Redding,  5;  Redding-Bieber  road  (12  miles  west 
of  Burney),  3;  Round  Mountain  (Shasta  County),  1;  Saint  John  (Glenn 
County),  3;  Salt  Creek  (6  miles  northwest  of  Baird,  Shasta  County),  1; 
Salmon  Mountains  (near  Etna  Mills,  Siskiyou  County),  5;  Shasta  Valley 


^  Univ.  Michigan  Mus.  Zool. 
E«  Mus.  Vert.  Zool. 
"Field  Mus.  Nat.  Hist 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  153 

(Siskiyou  County),  1;  Sherwood  (Mendocino  County),  3;  Siskiyou  Moun- 
tains (White  Mountain),  7;  Sisson  (Siskiyou  County),  8;  Sites  (Colusa 
County),  1;  Smith  River  (Del  Norte  County),  2;  South  Tolla  Bolly  Moun- 
tain (Trinity  County),  1;  Stillwater  (Shasta  County),  2;  Tehama,  1; 
Tower  House  (near  Bally  Mountain,  Shasta  County),  1;  Tule  Lake  (east 
side),  1;  Ukiah,  5. 

Oregon:  Ashland,  3;  Beaverton  (Washington  County),  1;  Blaine  (Tillamook 
County),  3;°°  Dog  Lake  Ranger  Station  (30  miles  southwest  of  Lakeview), 
1;  Douglas  County  (22  miles  east  of  Drew),  1;  Elk  Head  (Douglas 
County),  1;  Eugene,  3;  Farren  Ranger  Station  (13  miles  southwest  of 
Galice),  1;  Forest  Grove,  11;  Fort  Klamath,  1;'°  Gold  Beach,  4;"  Grants 
Pass,  10;  Hood  River,  4;  Klamath  Lake,  2;  Mapleton  (Lane  County),  1; 
Maupin  (Wasco  County),  8;  McCoy  (Polk  County),  4;  McKenzie  Bridge 
(10  miles  east.  Lane  County),  5;  Miller  (Sherman  County),  3;  Mount 
Hood  (north  slope,  2,800  feet  altitude),  1;  Naylox  (=Algoma,  Klamath 
Lake),  2;  Oregon  City,  1;  Philomath,  3;  Portland,  2;  Prospect  (Jackson 
County),  6;  Reston  (Douglas  County),  1;  Rogue  River  Valley  (near 
Grants  Pass),  4;  Roseburg,  5;  Salem,  3;"  Scottsburg  (Douglas  Coimty),  1; 
Siskiyou  (Jackson  County),  1;  The  Dalles,  20;  Tillamook,  1  ;"*  Wapinitia 
(Wasco  County),  1;  Warm  Springs  (Jefferson  County),  2;  Warm  Springs 
River  (Wasco  County),  2. 

Washington:  White  Salmon,  3. 

CITELLUS  BEECHEYI   SIERRAE,   sxjbsp.   nov. 
Sierra  Ground  Squtbrei- 

Type. — Collected  at  Emerald  Bay.  Lake  Talioe,  Calif.,  May  23, 
1897,  by  J.  Alden  Loring;  female  adult,  skin  and  skull,  no.  88421, 
IT.  S.  Natl.  Mus.  (Biological  Survey  collection)   (orig.  no.  4166.) 

Range. — Higher  parts  of  the  northern  Sierra  Nevada,  from  Plumas 
County  south  to  Mariposa  County  (upper  Merced  River)  (fig.  14). 
Zonal  range:  Transition  and  Canadian. 

External  characters. — Similar  in  size  and  color  of  upper  parts 
to  C.  h.  'beecheyi;  sides  of  head  more  grayish  (less  huffy) ;  feet  more 
whitish  (less  huffy) ;  under  parts  averaging  paler  (more  whitish) ; 
under  side  of  tail  more  grayish  (less  huffy).  Compared  with  C.  h. 
fisheri:  Head  and  upper  parts  distinctly  darker;  feet  more  whitish 
(less  huffy) ;  tail  darker  and  less  huffy  beneath. 

Cram  at  characters. — Skull  similar  to  that  of  heecheyi.,  but  aver- 
aging slightly  smaller,  except  in  the  postorbital  breadth,  which  ig 
greater. 

Color. — Winter  pelage  (type.  May  23)  :  Head  sayal  brown,  washed 
with  grayish  white;  sides  of  face  fuscous,  the  hairs  tipped  with 
grayish  white;  ears  fuscous  black,  shaded  on  posterior  margin  with 
grayish  buff;  general  tone  of  upper  parts  pale  sayal  brown,  flecked 
witii  huffy  white;  sides  of  neck  and  shoulders  with  a  heavy  wash  of 
grayish  white,  and  sides  of  body  less  heavily  washed  with  the  same ; 
hind  feet  grayish  white,  front  feet  pale  buffy  white;  tail  above, 
fuscous  black,  mixed  with  grayish  white;  tail  beneath,  mixed  buffy 
w^hite  and  fuscous  black;  under  parts  pinkish  buff. 

Variation. — In  some  specimens,  the  upper  parts  are  snuff  brown, 
flecked  with  cinnamon  buff  and  buffy  white;  the  head  is  sometimes 
pure  sayal  brown,  without  grayish  wash. 

Measurements. — Average  of  3  adult  males  from  vicinity  of  Lake  Tahoe 
(Emerald  Bay,  Tallac.  and  Emigrant  Gap)  :  Total  length,  452  (44(M70)  ;  tail 
vertebrae,  17S   (170-100)  :  hind  foot,  57.7    (54-63);   ear  from  notch   (dry),  20 


•'  Ilnlv.  Michigan  Mus.  Zool. 
"T  Field  Mus.  Nat.  Rist. 


3^54  -  NORTH  AMERICAN  FAUNA  [No.  56 

(19-21.5).  Average  of  10  adult  females  from  Emerald  Bay,  Dormer,  and  Little 
Yosemite:  Total  length,  422  (400-455)  ;  tail  vertebrae,  172  (159-184)  ;  hind  foot, 
56.2  (54-60)  ;  ear  from  notch  (dry),  20.3  (18.5-2.3).  Skull:  Average  of  5  adult 
males  from  Emerald  Bay,  Blue  Canyon,  and  Emigrant  Gap :  Greatest  length, 
58  (56.5-59.5)  ;  palatllar  length,  27.7  (26.5-29)  ;  zygomatic  breadth,  36.7  (34.9- 
37.8)  ;  cranial  breadth,  23.5  (22.4^24.6)  ;  iuterorbital  breadth,  14.1  (12.9^15.5)  ; 
postorbital  constriction,  16.1  (15.7-17.1)  ;  length  of  nasals,  20.9  (20.5-21.9)  ; 
maxillary  tooth  row,  11.4  (11-11.8).  Average  of  11  adult  females  from  Emerald 
Bay,  Blue  Canyon,  and  Donner:  Greatest  length,  56.6  (53.1-59.9);  palatllar 
length,  27   (25-28)  ;  zygomatic  breadth,  34.4  (33.1-36.9)  ;  cranial  breadth,  23.4 

(22.7-24.9)  ;   interorbital   breadth,   14    (13.5-15)  ;   postorbital  constriction,   16.2 

(15.2-17)  ;    length    of    nasals,    20.8    (19.5-21.8)  ;    maxillary    tooth    row,    11.1 

(10.5-11.7). 

Remarks. — The  Sierra  ground  squirrel  bears  a  close  resemblance 
to  typical  heecheyi.,  but  differs  in  certain  minor  characters  as  pointed 
out  above;  it  might  be  included  with  heecheyi  except  for  the  fact 
that  their  ranges  are  not  contiguous,  being  separated  by  the  range  of 
-fisheri^  the  pale  form  occupying  the  San  Joaquin  and  Sacramento 
Valleys.  Intergradation  with  fisheri  occurs  in  the  southern  Sierra 
Nevada  and  along  the  lower  slopes  on  the  western  side  of  the  range. 

Specimens  examiiied. — Total  number  39,  as  follows: 

California:  Big  Trees  (Calaveras  County),  1;  Blue  Canyon  (Placer  County), 
14;  Downieville,  1;  Emerald  Bay  (Lake  Tahoe),  5;  Emigrant  Gap  (Placer 
County),  1;  Little  Yosemite  (Mariposa  County),  1;  Markleeville  (Alpine 
County),  4;  Merced  River  (near  head),  3;  Quincy,  1;  Summit  (=Donner, 
Placer  County),  5;  Tallac  (Eldorado  County),  2;  Wawona  (south  fork 
Merced  River,  Mariposa  County),  1. 

CITELLUS  BEECHEYI  FISHERI  Meeeiam 
Fisher's  Ground  Sqxjireel 

Spermophilus  heecheyi  fisheri  Merriam,  Biol.  Soe.  Wash.  Proc.  8:  133,  Dec.  28, 

1893. 
[Spermophilus  fframmurus]  fisheri  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser. 

2:  88,  1901. 
Citellus  variegatus  fisheri  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3:  211, 

1903. 
Citellus  becchciji  fisheri  Grinuell,  Calif.  Acad.  Sci.  Proc.   (4)  3:  346,  1913. 
Otospennophilus  grammurus  fisheri  Miller,   U.   S.   Natl.   Mus.   Bull.   128:   181, 

1924. 

Type. — Collected  on  South  Fork  of  Kern  River,  3  miles  above 
Onyx,  Kern  County,  Calif.,  July  6,  1891,  by  A.  K.  Fisher;  male  sub- 
adult;  skin  and  skull,  no.|fff|,'U.  S.  Natl!  Mus.  (Biological  Survey 
collection)   (orig.  no.  741). 

Range. — Greater  part  of  central  California,  including  the  San 
Joaquin  and  Sacramento  Valleys  and  the  southern  Sierra  Nevada; 
north  on  the  eastern  side  of  the  Sacramento  River  to  southern  Butte 
County,  then  northeastward  to  Susanville;  east  to  the  western  side 
of  Pyramid  Lake,  Nev.,  and  to  Walker  Pass,  in  the  southern  Sierra 
Nevada,  Calif. ;  south  to  the  Tehachapi  Mountains ;  west  to  Cuyama 
Valley,  the  Carriso  Plain,  and  the  western  border  of  the  San  Joaquin 
Valley  (fig.  14).    Zonal  range:  Upper  Sonoran  and  Transition. 

External  characters. — Similar  in  size  to  C .  h.  'heecheyi,  but  hind 
feet  shorter ;  coloration  paler,  both  above  and  below ;  light  markings 
on  shoulders  more  prominent  and  clearer  white. 

Cranial  characters. — Skull  similar  to  that  of  heecheyi  but  averag- 
ing smaller,  especially  in  the  females;  zygomata  less  widely 
expanded. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  155 

Color. — Smnmer  pelage  (Kern  Valley)  :  Top  of  head  and  face 
light  pinkish  cinnamon;  sides  of  face  pale  smoke  gray;  a  large  patch 
of  clear  creamy  white  on  each  shoulder,  this  color  extending  to  the 
middle  of  the  back  in  two  narrow  stripes  separated  by  a  dark  area 
more  or  less  triangular  in  shape;  rest  of  upper  parts  about  wood 
brown  in  general  tone,  flecked  with  patches  of  creamy  white;  feet 
pale  buff  or  buffy  white ;  tail  mixed  fuscous  black  and  pmkish  buff ; 
under  parts  creamy  white  to  pinkish  buff'.  Winter  pelage  (Modesto, 
February)  :  General  tone  of  upper  parts  (excepting  head)  pale 
smoke  gray,  faintly  washed  with  pale  pinkish  buff;  under  parts  pale 
pinkish  buff ;  tail  mixed  fuscous  black  and  pale  pinkish  buff. 

Molt. — The  annual  molt  may  occur  at  any  time  between  May  and 
August;  an  adult  male  from  Modesto,  taken  May  8,  shows  new  pelage 
coming  in  on  the  head,  nape,  and  fore  back;  a  male  taken  at  JNIilford 
(Honey  Lake),  June  20,  shows  new  pelage  covering  the  posterior 
half  of  the  body,  and  small  areas  on  the  head,  shoulders,  and  fore 
back;  a  male  from  Biggs,  Butte  County,  shows  small  areas  of  new 
pelage  on  the  crown  and  in  the  middle  of  the  back,  behind  the 
shoulders;  a  male  from  Carriso  Plain,  taken  August  1,  shows  new 
pelage  on  the  head  and  a  large  patch  on  the  hinder  back. 

Measurements. — Average  of  7  males  (adult  and  subadult)  from  Kern  River 
Valley  and  Walker  Basin:  Total  length,  442  (415H175)  ;  tail  vertebrae,  183  (175- 
19S)  ;  hind  foot,  57.6  (54-62)  ;  ear  from  notch  (dry),  1S.4  (17-2C0.  Average  of 
4  adult  females  from  Kern  River  Valley:  Total  length,  407  (390-427)  ;  tail  verte- 
brae, 162  (155-170)  ;  hind  foot,  52.7  (50-56)  ;  ear  from  notch  (drv),  18.3  (17- 
20).  Average  of  11  adult  males  from  Modesto:  Total  length,  457  (433-500)  ; 
tail  vertebrae,  107  (140-190)  ;  hind  foot,  60.1  (55-63)  ;  ear  from  notch  (dry), 
19.3  (17.5-21)  ;  average  of  4  adult  females  from  Modesto:  423;  168;  55.4;  17.7. 
Skull:  Average  of  4  adult  males  from  Kern  River  Vallev  and  Walker  Basin: 
Greatest  length,  59.3  (57-60.9)  ;  palatilar  length,  28.7  '(27.5-30)  ;  xvgomatic 
breadth,  36.9  (36.0-37.4)  ;  cranial  breadth,  24.2  (23.8-24.7)  ;  interorbital"  breadth, 
13.5  (11.5-14.3)  ;  postorl>ital  constriction,  16  (15.2-17)  ;  length  of  nasals.  22.2 
(21.5-22.8)  ;  maxillary  tooth  row,  11.8  (11.7-12).  Average  of  3  adult  females 
from  Kern  River  Valley:  Greatest  length.  55.8  (55.6-50)  ;  ]ialatilar  length.  26.5 
(26-27)  ;  zygomatic  breadth,  34.2  (33.9-.34.6)  ;  cranial  breadth,  23.1  (22.4-23.5)  ; 
interorbital  breadth,  13.7  (13.4-14)  ;  postorbital  constriction.  15.3  (14.6-16)  ; 
length  of  nasals,  20.1  (19.6-20.8)  ;  maxillary  tooth  row,  11.4  (11.1-11.7).  Aver- 
age of  15  adult  males  from  Modesto:  Greatest  length,  59.5  (55.5-62)  ;  palatilar 
length.  29.9  (27.5-31)  ;  zygomatic  breadth.  37.5  (.•^4.2-.3S.9)  ;  cranial  breadth, 
23.8  (22.2-24.9)  ;  interorbital  breadth.  14.5  (13..3-16.5)  ;  postorbital  constric- 
tion, 16  (15-16.9)  ;  length  of  nasals,  21.8  (20.2-22.S)  :  maxillary  tooth  row,  11.7 
(11.1-12.3).  Average  of  6  adult  females  from  Modesto:  Gre.-\test  length.  .56.3 
(55.3-.57.5)  ;  palatilar  length,  27.1  (26-28)  ;  zygomatic  lireadth.  35  (33.8-35.8)  ; 
cranial  breadth,  23.4  (22.7-24.8)  ;  interorbital  breadth,  13.7  (12.6-14.7)  ;  post- 
orbital constriction,  15.5  (14.6-15.9)  ;  length  of  nasals,  20  (19.2-20.7)  ;  maxillary 
tooth  row,  11.6  (10.9-12.) 

Remarks. — Fisher's  ground  squirrel  is  about  the  size  of  heecheyi., 
but  averages  decidedly  paler  in  color;  it  is  similar  to  O.  h.  parindiis  in 
color,  but  is  distinctly  larger.  Over  its  extensive  range  in  botli  valley 
and  mountain  country  it  is  subject  to  considerable  variation  in  color, 
and  many  individual  specimens  are  scarcely  different  from  some 
individuals  of  heecheyi. 

Intergradation  with  heecheyi  occurs  along  the  western  side  of  the 
San  Joaquin  Valley  and  in  the  Tehachapi  Mountains,  with  sierrae  in 
tlie  foothills  of  the  Sierra  Nevada  and  with  douglasii  in  Butte 
County. 


156  NORTH  AMERICAN  FAUNA  [No.  56 

Specimens  examined. — ^Total  number,  279,  as  follows : 

Caifornia:  Alcalde  (Fresno  County),  3;  Alila  ( =Earlimart,  Tulare  County), 
8;  Alta  Peak  (Kaweah  River,  Tulare  County),  1;  Aspen  Meadow  (Yosemite 
National  Park),  4;  Auburn  (Placer  County),  2;  Bakersfield  (Smiles  north- 
east), 1,"  Biggs,  3;  Bodflsh  (Kern  County),  1;"  Camp  Badger  (Tulare 
County),  1;  Cannell  Meadow  (Tulare  County),  1;°*  Carbondale  (Amador 
County),  2;  Carriso  Plain,  5;  Claribel  (Stanislaus  County),  1;°*  Colusa  (6 
miles  east),  1;  Coulterville,  1;  Cuyama  Valley  (San  Luis  Obispo  County),  2; 
Dos  Palos,  1 ;  Dry  Creek  (Butte  County),  1 ;  "^  Earlimart,  2 ;  ^  Eshom  Valley 
(Tulare  County),  1;  Feather  River  Station  (Butte  County),  2;  '*  Fort  Tejon 
(Kern  County),  13;  Fresno  4;  Fresno  Flat  (Madera  County),  4;  Grabner 
(Fresno  County),  6;^°  Greenville  (Plumas  County),  1;  Horse  Corral  Mead- 
ows (Fresno  County),  1;  Jackass  Meadow  (Tulare  County),  1 ;  **  Jordan 
Hot  Springs  (Tulare  County),  1 ; '^  Kern  Lake  (Tulare  County),  1;  Kern 
River  (15  miles  northeast  of  Bakersfield),  1;  Kern  River  (Isabella  and  12 
miles  below  Bodfish),  4;  °*  Kern  River  (South  Fork,  near  Onyx),  12;  Kern- 
ville,  2;  La  Grange  (Stanislaus  County),  1;  Lemoore,  3;  Long  Valley  (Las- 
sen County),  1;  Los  Banos  (Merced  County),  9;  Maricopa,  4;^  Marysville, 
1;  Marysville  Buttes,  7;  Milford  (Lassen  County),  2;  Milo  (Tulare  County), 
2;  Mineral  King  (East  Fork  Kaweah  River,  Tulare  County),  1;  Modesto, 
31 ;  Mono  Flats  (Santa  Barbara  County),  2;  Mountain  House  (6  miles  south- 
west of  Downieville ) ,  2 ;  Mount  Finos,  7 ;  Mount  Whitney,  1 ;  Nevada  City, 
2;  Orosi  (Tulare  County),  7;  Oroville  (Butte  County),  1;^  Pacheco  Pass 
(Santa  Clara  County),  2  ;  Placerville  (Eldorado  County),  3  ;  Plumas  County, 
1;  Porterville,  1;  Prattville  (Plumas  County),  2;  Raymond  (Madera  Coun- 
ty), 2;  Redwood  Mountain  (General  Grant  National  Park),  1 ;  Ripon,  2;  Rose 
Station  (6  miles  north  of  Old  Fort  Tejon),  2;  Sacramento,  3;  Salt  Springs 
(Fresno  River,  30  miles  east  of  Raymond),  1;  San  Emigdio  (Kern  County), 
1;  San  Emigdio  Canyon,  2;  San  Emigdio  Creek,  2;  ^  Sierra  Valley  (Plumas 
County),  2;  Sequoia  National  Park,  2;  Soquel  Mill  (head  of  North  Fork  of 
San  Joaquin  River),  2;  Sunset  Station  (near  Maricopa,  Kern  County),  1; 
Susanville.  1;  Taylor  Meadow  (Tulare  County),  5;^  Tehachapi,  2;  Teha- 
chapi  Peak,  3;  Tejon  Canyon,  3;  Tejon  Pass,  4;  Three  Rivers  (Tulare 
County),  2;  Tipton  (Tulare  County),  5;°*  Tracy,  1;  Trout  Creek  (Tulare 
County,  altitude  6,000  feet),  3  ; ''  Trout  Meadows  (Tulare  County),  1 ;  Volta 
(Merced  County),  2;  Walker  Basin  (Kern  County),  1;  Walker  Pass  (Kern 
County),  4;  Weldon  (Kern  County),  3;  Yankee  Hill  (Butte  County),  1; 
Yosemite  Valley,  3;  Zaca  Lake  (Santa  Barbara  County),  1. 

Nevada:  Carson  City,  1;  Genoa,  1;  Glenbrook  (Douglas  County),  3;  Pyramid 
Lake  (west  side),  4;  Reno,  3;  Verdi,  6;  Virginia  Mountains  (Washoe 
County),  1. 

CITBLLUS  BEECHEYI  PARVULUS  Howell 

Lessee  Califoenla.  Ground  Squieeel 
(Pis.  26,  A;  31,  A) 

Citellus  heecheyi  parviilus  Howell,  Jour.  Mammal.  12 :  160,  May  14,  1931. 

Type. — Collected  in  Shepherd  Canyon,  Argus  Mountains,  Calif., 
April  30,  1891,  by  A.  K.  Fisher;  female  subadult,  skin  and  skull,  no. 
^^%^,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig.  no. 
569  J. 

Range. — Desert  ranges  of  southern  California  (except  the  Provi- 
dence Mountains) ;  north  to  Owens  Valley;  south  to  the  San  Jacinto 
Mountains  (fig.  14).  Zonal  range:  Mainly  Upper  Sonoran  and 
Transition,  but  extending  into  Lower  Sonoran. 

Oranial  characters. — Similar  to  O.  h.  -fislieri^  but  smaller. 

Color. — Not  appreciably  different  from  that  of  -jisheri. 

=8  Mus.  Vert.  Zool. 

^  Cleveland  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  157 

Measurements. — Average  of  10  adult  males  from  Panamiut  Mountains,  Argus 
Mountains,  and  Owens  Valley :  Total  length,  411.8  (383-435)  ;  tail  vertebrae, 
162.8  (155-179)  ;  hind  foot,  54.8  (50-58)  ;  ear  from  notch  (dry),  19.8  (18-21). 
Average  of  12  adult  females  from  same  section:  Total  length,  410  (885-455)  ; 
tail  vertebrae,  163  (145-180)  ;  hind  foot,  52.9  (50-56)  ;  ear  from  notch  (dry), 
19  (17-22).  Skull:  Average  of  7  adult  males  from  Panamint  Mountains,  Argus 
Mountains,  Lone  Pine,  and  Owens  Lake:  Greatest  length,  56.3  (53.9-60.5)  ; 
palatUar  length,  26.8  (25-28)  ;  zygomatic  breadth,  35.8  (34-36.4)  ;  cranial 
breadth,  23.3  (22.7-24.4)  ;  interorbital  breadth,  12.8  (11.8-13.3)  ;  postorbital 
constriction,  14.9  (13.6-16.1)  ;  length  of  nasals,  20.9  (19.4-22.2)  ;  maxiUary  tooth 
row,  11.1  (10.9-11.8).  Average  of  9  adult  females  from  same  region:  Great- 
est length,  53.9  (52.2-54.8)  ;  palatilar  length,  25.4  (25-26)  ;  zygomatic  breadth, 
33.6  (32.6-34.7)  ;  cranial  breadth,  23.2  (22.8-24.1)  ;  interorbital  breadth,  13.3 
(12.4-14.1)  ;  postorbital  constriction,  15.8  (14.8-16.4)  ;  length  of  nasals,  19.4 
(18.&-20.8)  ;  maxillary  tooth  row,  11.3  (10.8-11.7). 

Weight. — One  old  female  from  Olancha  weighed  655  g. 

Remarks. — ^In  the  original  description  of  this  race,  the  present 
writer  defined  its  range  as  extending  southward  to  the  San  Pedro 
Martir  Mountains,  Baja  California;  since  then,  Huey  (1931,  p.  18) 
has  described  the  form  from  northern  Baja  California  as  G.  h. 
liudipes^  and  as  a  result  of  further  intensive  study  of  a  large  series  of 
specimens  from  the  type  region  of  nudipes  and  from  extreme  southern 
California,  it  seems  proper  to  restrict  the  name  pai^ulus  to  the 
small  California  race  as  far  south  as  the  San  Jacinto  Mountains,  and 
to  refer  the  series  from  San  Diego  County  southward  to  nudipes. 

Huey  objects  to  the  recognition  of  parvulus  on  the  ground  that 
there  is  no  appreciable  difference  between  specimens  from  the  type 
locality  of  fisheri  (South  Fork  of  Kern  River)  and  those  from  the 
type  locality  of  parvulus  (Argus  Mountains) ;  comparison  of  the 
cranial  measurements  of  seven  specimens  (four  males,  three  females) 
of  fisheri  from  the  type  region  given  on  page  155  with  the  measure- 
ments of  parvulus  (above)  shows,  however,  a  decided  difference  in 
size  of  the  skulls.  It  is  true  that  the  topotype  series  of  -fisheri  is 
slightly  smaller  in  average  cranial  measurements  than  the  series  from 
the  San  Joaquin  Valley,  but  the  difference  in  size  is  much  less  than 
between  topotypes  of  fisheri  and  of  parvulus. 

The  present  race  intergrades  with  fsheri  in  the  Piute  Mountains, 
with  0.  h.  beecheyi  in  the  San  Bernardino  Mountains,  and  with 
nudipes  in  the  San  Jacinto  Mountains.  The  series  from  the  San 
Bernardino  Mountains  is  so  nearly  intermediate  between  heecheyi 
and  parvulus  that  it  makes  little  difference  which  name  is  applied 
to  it ;  in  fact,  some  specimens  are  practically  typical  of  one  race,  some 
of  the  other.  The  skulls  average  smaller  than  those  of  heecheyi. 
The  series  from  the  San  Jacinto  Mountains  is  likewise  intermediate 
between  parvulus  and  nudipes,  but  a  little  nearer  parmdus.  The 
skulls  average  a  little  smaller  than  the  San  Bernardino  series. 

Specimens  examined. — Total  number,  160,  as  follows : 

California:  Argus  Range  (Inyo  County),  3;  Andreas  Canyon  (Riverside County), 
1;**  Banning,  13;  Cabazon  (Riverside  County),  11;°*  Cameron  (Kern 
County),  2;  Coso  (Inyo  County),  6;  El  Ca.sco  (Riverside  County),  1; 
Hesperia  (San  Bernardino  County),  2;  Independence,  4;*"  Independence 
Creek  (6.500  feet  altitude),  1;  Jackass  Spring,  Panamint  Mountains, 
11 ;~  "Little  Lake  (Inyo  County),  2;  Little  Onion  Valley  (Inyo  County), 
1;"  Little  Cottonwood  Creek  (Inyo  County),  1;°"  Lone  Pine,  5;  Mount 
William.son    (N,   E.   base),   Owens   Valley,   3;"   Old   Camp   Independence, 

"Mus.  Vert.  Zool. 

«'  Cleveland  Mus.  Nat.  Hist. 

"  Two  in  Cleveland  Mus.  Nat.  Hist. 


158  NORTH  AMERICAN  FAUNA  [No.  56 

Owens  Valley,  1;"  Olancha  (Inyo  County),  1;*"  Oro  Grande,  8;  Owens 
Lake,  6 ;  Owens  Valley,  2 ;  Panamint  Mountains,  5 ;  Piute  Mountains,  1 ; 
Palm  Springs,  8;  Reclie  Canyon  (San  Bernardino  County),  4;  Riverside, 
1;  San  Bernardino,  7;  San  Bernardino  Mountains,  15;  San  Jacinto 
Mountains,  32;'°  Snow  Creek  (near  Wliitewater,  Riverside  County),  1;^ 
Victorville,  1."" 

CITELLUS  BEECHEYI  NUDIPES  HuEY 

Juarez  Ground  Squirrei. 

CiteUvs  beecheyi  nndlpes  Huey,  San  Diego  Soc.  Nat.  Hist.  Trans.  7:  18,  Oct.  6, 
1931. 

Type. — Collected  at  Hanson  Laguna.  Sierra  Jnarez,  Baja  Cali- 
fornia, Mexico  (latitude  31°  58'  north,  longitude  115°  53'  west;  alti- 
tude 5,200  feet),  October  13,  1926,  by  Frank  Stephens;  female  adult, 
skin  and  skull,  no.  2015,  San  Diego  Soc.  Nat.  Hist. 

Range. — Northern  Baja  California  and  extreme  southwestern 
California,  including  most  of  the  western  half  of  San  Diego  County 
(fig.  14),    Zonal  range:  Upper  and  Lower  Sonoran  and  Transition. 

External  characters. — Similar  to  C.  h.  heecheyi  but  smaller  and 
with  paler  feet  and  under  parts  and  more  conspicuous  shoulder 
patches;  similar  in  size  to  C.h.  parvulus  but  darker. 

Cranial  characters. — Skull  closely  similar  to  that  of  parvulus; 
smaller  than  those  of  heecheyi  and  C.  h.  fisheri. 

Color. — Fresh  winter  pelage  (tcpotypes,  October)  :  Head  wood 
brown;  shoulder  patches  grayish  white,  strongl}'^  contrasted  with 
the  color  of  the  back:  dorsal  area  snuff  brown,  flecked  with  light 
pinkish  cinnamon:  sides  more  heavily  flecked  with  grayish  white; 
feet  cartridge  buff;  under  parts  grayish  white,  faintly  washed  with 
pale  pinkish  buff;  tail  black,  mixed  with  white  or  buffy  white.  Sum- 
mer pelage  (San  Pedro  Martir  Mountains,  July)  :  Dorsal  area  paler 
(less  brownish)  than  in  winter,  the  general  tone  on  the  back  near 
wood  brown,  with  a  pinkish  tinge,  the  sides  more  grayish.  In  cer- 
tain summer  specimens  in  worn  pelage — notably  one  from  San 
Telmo,  August  22— the  general  tone  of  the  dorsal  area  is  near  cinna- 
mon. In  some  also,  the  anterior  back,  between  the  white  shoulder 
patches,  is  blackish  brown,  due  in  large  part  to  the  wearing  away  of 
the  tips  of  the  hairs  and  exposure  of  the  dark  basal  portion. 

Molt. — A  specimen  from  the  San  Pedro  Martir  Mountains,  taken 
June  29,  is  in  badly  worn  pelage  and  shows  a  fresh  pelage  coming 
in  over  the  anterior  half  of  the  back ;  several  from  Trinidad  Valley, 
taken  July  10  to  16,  show  a  fresh  pelage  on  the  rump,  the  rest  of  the 
back  being  much  worn. 

Measurements. — Average  of  8  adult  males  from  San  Pedro  Martir  Moun- 
tains: Total  length.  411.6  (386-442)  ;  tail  vertebrae.  177  (162-196)  ;  hind  foot, 
56.1  (52-62)  ;  ear  from  notch  (dry),  18.5  (17-20).  Average  of  11  adult  females 
from  Hanson  Laguna,  Trinidad  Valley,  and  San  Pedro  Martir  Mountains : 
Total  length,  397  (357-435)  ;  tail  vertebrae.  156.5  (140-186)  ;  hind  foot,  53.7 
(50-57)  ;  ear  from  notch  (dry),  19  (17-20).  Skull:  Average  of  6  adult  males 
from  Hanson  Lagima.  Trinidad  Vallev.  San  Pedro  Martir  Mountains,  and 
San  Telmo:  Greatest  length,  56.8  (54.859.5);  palatilar  length,  27  (26-28); 
zygomatic  breadth,  35.2  (32.8-35.9)  ;  cranial  breadth,  23.5  (22.8-24.4)  ;  interor- 
bital  breadth,  13.7   (11  .-1-14.8)  ;  postorbital  constriction,  16    (15.2-18.1)  ;  length 


<=9Mus.  Vert.  Zool. 

f^  Cleveland  Mus.   Nat.  Hist. 

"2  Eighteen  in  Mus.  Vert.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  159 

of  nasals,  20.4  (1&-21.7)  ;  maxillary  tooth  row,  11.2  (10.6-12).  Average  of 
10  adult  females  from  San  Pedro  Martir  Mountains  and  Hanson  Laguna : 
Greatest  length,  54.6  (51.6-56.1)  ;  palatilar  length,  25.8  (23.5-27)  ;  zygomatic 
breadth,  34.2  (32.3-35.2)  ;  cranial  breadth,  23  (22.2-24.7)  ;  interorbital  breadth, 
13.3  (12.2-14.6)  ;  postorbital  constriction,  16.1  (15.6-17.3)  ;  length  of  nasals, 
19.5  (17.5-20.6)  ;  maxillary  tooth  row,  11.1  (10.4-11.7). 

Remarks. — This  is  a  small,  dark  race,  nearest  in  general  coloration 
to  heecheyi,  but  with  more  conspicuous  white  shoulder  patches  and 
paler  under  parts.  It  averages  slightly  larger  in  external  measure- 
ments than  parvulKS,  though  the  skulls  of  these  two  races  are  closely 
s-'imilar.  Wliere  their  ranges  meet  in  the  mountains  of  San  Diego 
County,  Calif.,  many  intermediate  specimens  are  found.  In  the 
series  examined  from  Santa  Ysabel,  Witch  Creek,  Twin  Oaks, 
Jacumba,  Nachoguero  Valley,  and  Dulzura,  some  of  the  specimens 
are  fairly  typical  of  nudipes.^  while  others  are  much  paler  and  might 
almost  as  well  be  referred  to  parvulus.  A  large  series  from  San 
Ysidro  Ranch,  on  the  Mexican  boundary  line,  19  miles  east  of  the 
Pacific  Ocean,  are  very  similar  in  size  and  general  coloration  to 
nudipes.,  but  have  somewhat  more  buffy  under  parts,  thus  showing 
approach  to  heecheyi.  The  series  from  around  San  Diego  Bay  is 
still  more  like  heecheyi  in  color,  though  agreeing  with  nudipes  in 
smaller  size  of  skull  and  hind  feet.  A  series  of  10  specimens  from 
Point  Loma  is  about  as  dark  on  the  upper  parts  as  heecheyi  but  the 
under  parts  are  decidedly  paler.  Four  specimens  from  San  Diego 
and  one  from  mouth  of  Tia  Juana  River  agree  both  in  color  and  size 
with  typical  nudipes  except  for  somewhat  more  buify  under  parts. 
Another  individual  from  Tia  Juana  River  is  about  as  dark  as 
heecheyi,  both  above  and  below. 

Specimens  examined. — Total  number,  163,  as  follows: 

Baja  California:  Descanso  Bay  (north  side),  1;"^  EI  Rayo,  Hanson  Laguna 
Mountains,  2 ;  Ensenada,  1 ;  Hanson  Laguna,  1 ;  Las  Eucinos,  1 ;  ~  Nacho- 
guero Valley  (near  Monument  2.";7,  Mexican  boundary  line),  5;  San  Pedro 
Martir  Mountains,  22  (including  La  Grulla.  2;  I'inyon,  2;  Rancho  San 
Antonio,  9;  Rancho  Santo  Tomas,  1;  Vallecitas,  5);  San  'JVlnio,  1;  San 
Quentin,  3;*^  San  Matias  Pas.s,  1;  San  Ysidro  Rancli  (near  Monument  250, 
Mexican  boundary  line),  15;  Tecarte  Valley,  1;  Trinidad  Valley,  6."° 

California:  Campo  (San  Diego  County),  1;"^  Chula  Vista,  3;"'  Cuyamaca 
Mountains  (San  Diego  County),  4;"  Dulzura  (San  Diego  County),  16; 
Grapevine  Spring  (San  Diego  County),  1;'"  Jacumba  Springs,  5;  Jamul 
Creek  (San  Diego  County),  1;  Julian  (San  Diego  County),  8;*"  Laguna 
Mountains  (San  Diego  County),  16;  Lakeside  (San  Diego  County),  2;"' 
Mountain  Spring  (4  miles  north  of  Monument  231,  ]\Iexican  boundary 
line),  8;  Oceanside  (San  Diego  County),  2;  Pacific  Ocean,  at  Mexican 
boundary  line,  1;  Point  Loma  (San  Diego  County),  10;"  San  Diego,  6; 
Santa  Ysabel  (San  Diego  County).  4:  Tia  Juana  River  (mouth).  2;  Twin 
Oak.s  ( San  Diego  ( 'ounty ) ,  2  :  Warner  Pass  ( San  Diego  County) ,  3  ;  "  Witch 
Creek  (San  Diego  County),  8." 

CITELLUS  BEECIIEYI  RUPINARUM  Huey 

Catavina  Ground  Squirisel 

Citellus  heecheyi  rupinarum  Huey,  San  Diego  Soc.  Nat.  Hist.  Trans.  7 :  17,  Oct. 
6,  1931. 

Type. — Collected  at  Catavina,  Baja  California,  Mexico  (hititude 
29°54'  north,  longitude  114°57'  west),  October  9,  1930,  by  Laurence 

*'  Mus.  Vert.  Zool. 

•^  San  Difigo  Soc.  Nat.  Hist. 

"Field  Mus.  Nat.  Hist. 


IgO  NORTH  AMERICAN  FAUNA  [No.  56 

M.  Huey ;  female  subadult,  sMn  and  skull,  no.  8251,  San  Diego  Soc. 
Nat.  Hist. 

Range. — Deserts  of  central  Baja  California,  south  of  the  San  Pedro 
Martir  Mountains ;  southern  limits  unknown  (fig.  14).  Zonal  range: 
Lower  Sonoran. 

External  characters. — Similar  to  C.  &.  nudipes,  but  paler  (less 
brownish)  dorsally  and  without  darker  area  on  anterior  back; 
shoulder  patches  less  prominent;  head  slightly  paler  (less  reddish). 
Closely  similar  to  C.  h.  parvulus.,  but  shoulder  patches  less  distinct 
and  front  feet  apparently  darker  buff. 

Cranial  characters. — Skull  very  similar  to  that  of  nudipes.,  averag- 
ing slightly  smaller  and  relatively  narrower  across  zygomata. 

Color. — Winter  pelage  (Oct.  9) :  Head  pale  wood  brown  or  avel- 
laneous;  shoulder  patches  grayish  white  or  creamy  white;  dorsal 
area  sayal  brown,  flecked  with  pinkish  buff;  feet  cartridge  buff; 
under  parts  creamy  white,  washed  with  pinkish  buff  on  lower  abdo- 
men ;  tail  mixed  black  and  pale  pinkish  buff. 

Molt. — A  specimen  from  San  Fernando,  taken  September  5,  shows 
patches  of  new  pelage  on  the  top  of  the  head  and  between  the  shoul- 
ders, the  remainder  of  the  pelage  being  moderately  worn.  A  speci- 
men from  Catavina,  taken  on  October  9,  has  acquired  a  nearly  com- 
plete new  pelage  except  on  the  nape  and  shoulders. 

Measurements. — Average  of  4  adult  females:  Total  length,  421    (415-425) 
tail   vertebrae,    181    (170-188)  ;    hind    foot,    55.      Skull:  Average    of    4    adult 
females:    Greatest   length,    54.2    (53.2-55.3);    palatilar   length,    26.1    (25-27) 
zygomatic  breadth.  32.9    (.32.3-34.5)  ;   cranial  breadth.   22.9    (22.6-23.5)  ;   inter 
orbital    breadth,    12.2     (11.4-14)  ;    postorbital    constriction,    16.1     (15.7-16.4) 
length  of  nasals,  18.9  (18.5-19.4)  ;  maxillary  tooth  row  11.2  (10.8-11.6). 

Remarks. — This  pale  subspecies  is  similar  in  color  to  parvulus  of 
California;  its  range  is  a  desert  area  in  Baja  California  between 
the  ranges  of  nudipes  and  C .  atHcapillus,  both  of  which  are  darker 
in  color.  No  males  of  this  race  have  been  examined  and  only  four 
females,  so  that  the  skull  characters  and  color  variations  are  im- 
perfectly known. 

Specimens  examined. — Total  number,  4,  as  follows : 
Baja  California:  Catavina,  3;  "  San  Fernando,  1. 

CITELLUS  BEECHEYI  NESIOTICUS  Eixiot 

Catalina  Ground  Sqitireel 

Gitellus  nesioticus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3:  263,  Mar.  8, 

1904. 
Citellus  beecheyi  nesioticus  Grinnell,  Calif.  Acad.  Sci.  Proc.  (4)  3:  345,  1913. 
Otospermophihis  nesioticus  Miller,  U.  S.  Natl.  Mus.  Bull.  128:  181,  1924. 

Type. — Collected  on  Santa  Catalina  Island,  Calif.,  February  8, 
1903,  by  John  Eowley ;  male  adult,  skin  and  skull,  no.  11722,  Field 
Mus.  Nat.  Hist. 

Range. — Catalina  Island,  Calif,  (fig.  14).  Zonal  range:  Upper 
Sonoran. 

External  characters. — Similar  to  G.  h.  heecheyi.,  but  hind  foot 
averaging  larger ;  coloration  very  similar,  but  averaging  more  gray- 
ish (less  brownish)  and  light  shoulder  stripes  less  conspicuous. 

«^  San  Diego  Soc.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  161 

Cranial  characters. — Skull  similar  to  that  of  heecheyi^  but  averag- 
ing larger  jnasal  branches  of  premaxillae  broader. 

Color. — Winter  pelage  (February-April)  :  Head  and  face  pink- 
ish cinnamon  or  grayish  white,  more  or  less  darkened  ^yhen  worn 
by  the  fuscous  bases  of  the  hairs;  ears  fuscous,  broadly  bordered 
on  posterior  portion  with  drab;  upper  parts  mixed  cinnamon  buff 
and  buffy  white,  darkened  by  the  fuscous  bases  of  the  hairs;  shoul- 
ders washed  with  grayish  or  buffy  white,  this  wash  continuing  as  an 
indistinct  stripe  on  each  side  of  the  dorsal  area  to  the  middle  of 
the  body;  sides  flecked  wdth  rather  large,  irregular  spots  of  white 
or  buffy  white;  tail  above,  fuscous  or  fuscous  black,  mixed  with 
buffy  white ;  tail  beneath,  pinkish  buff,  mixed  with  fuscous  black  and 
edged  with  pale  buff;  feet  cartridge  buff;  under  parts  pinkish  buff 
or  warm  buff. 

Variation. — ^The  type  specimen  has  a  large  patch  of  black  on  the 
forehead,  this  being  the  only  specimen  in  the  series  of  18  examined 
that  shows  such  a  marking.  Certain  specimens  in  worn  winter 
pelage  show  a  large  area  of  fuscous  on  the  back  from  the  occiput  to 
the  middle  of  the  body. 

Measurements. — Average  of  12  adults  (4  males,  8  females)  from  Catalina 
Island:  Total  length,  451  (432-476)  ;  tail  verterbrae,  172  (154-188)  ;  hind  foot, 

59.1  (5.5-63.5)  ;  ear  from  notch  (dry),  20.3  (19-21.8).  Skull:  Average  of  4 
adult  males  from  Catalina  Island:  Greatest  length,  60.7  (59.1-61.9)  ;  palatilar 
length,  29.2  (28-30)  ;  zygomatic  breadth,  38.5  (36.8-40.1)  ;  cranial  breadth, 
24.5   (23.5-25.4)  ;  interorbital  breadth,  15.5    (14.9-16)  ;  postorbital  constriction, 

15.2  (14.7-15.8)  ;  length  of  nasals,  22.6  (21.7-23.5)  ;  maxillary  tooth  row, 
11.9  (11.8-12).  Average  of  11  adult  females  from  same  locality:  Greatest 
length.  58  (56.9-60.3)  ;  palatilar  length,  27.2  (26-28)  ;  zygomatic  breadth,  36.4 
(35-37.5)  ;  cranial  breadth,  23.7  (22.9-24.4)  :  interorbital  breadth,  14.5  (13.5- 
15.9)  ;  postorbital  constriction,  15.3  (14.6-16.2)  ;  length  of  nasals,  21.2  (20.6-22)  ; 
maxillary  tooth  row,  11.7  (11.2-12.2). 

Remarks. — This  island  form  is  evidently  derived  from  the  stock  of 
the  adjacent  mainland,  from  which  it  has  diverged  but  slightly. 
Since  there  is  complete  intergradation  of  characters  between  nesioti- 
cvs  and  heecheyi.^  and  certain  specimens  from  the  two  series  are  prac- 
tically identical,  the  island  form  is  treated  as  a  subspecies. 

Specimens  examined. — Total  number,  18,  from  Catalina  Island. 

CITELLUS  ATRICAT'ILLUS    (Bkyant) 
Lower  C.\ijforma  Rock  Squirrel 

Spermophilus  granwinrus  atricapiUus  Bryant,  Calif.  Acad.   Sci.  Proc.    (2)   2: 

26,  June  20,  1889. 
[Citellus  variepatus]   atricapiUus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.   Ser. 

4:  150,  1904. 
Otospermophilus  grammurus  atricapiUus  Miller,  U.   S.   Natl.  Mus.   Bull.   128: 

180,  1924. 

Type. — None  designated;  based  on  29  specimens  from  Comondii, 
Baja  California,  formerly  in  the  collection  of  the  California  Acad- 
emy of  Sciences,  but  destroyed  by  fire  in  1906, 

Range. — Southern  Baja  California,  from  the  Sierra  de  San  Fran- 
cisco (Lat.  28°)  south  to  Comondu  (and  possibly  farther)  (fig.  13). 
Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  C.  heecheyi  heecheyi  but  darker, 
especially  on  the  head  and  anterior  half  of  the  back ;  tail  averaging 
longer. 

154970—38 11 


IQ2  NORTH  AMERICAN  FAUNA  [No.  56 

Cranial  characters. — Skull  similar  to  that  of  heecheyi,  but  aver- 
aging slightly  smaller. 

Color. — (Topotypes,  winter  pelage)  :  Head  fuscous  black,  spar- 
ingly sprinkled  with  pinkish  buff;  eye  ring  buffy  white;  ears  fus- 
cous black,  narrowly  margined  on  posterior  border  with  pale  buff; 
anterior  half  of  back  fuscous  black,  the  sides  of  neck  and  shoulders 
tipped  with  buffy  white,  leaving  a  well  defined  dark  triangular  patch 
uniting  with  the  color  of  the  head;  hairs  on  posterior  back  fuscous 
at  base,  tipped  with  pinkish  cinnamon  and  pale  pinkish  buff;  front 
feet  pale  buff ;  hind  feet  pinkish  buff ;  tail  mixed  fuscous  black  and 
pale  buff;  under  parts  fuscous,  overlaid  with  pale  buff. 

Afolt. — A  specimen  from  Comondu,  September  27,  had  nearly  com- 
pleted the  molt.  New  pelage  had  apparently  come  in  from  both 
directions,  covering  all  the  body  except  a  small  area  just  behind 
the  shoulders.  A  female  from  San  Ignacio,  October  15,  shows  new 
pelage  covering  the  posterior  portion  of  the  body  almost  to  the 
shoulders. 

Measurements. — Average  of  12  adults  (7  males,  5  females)  from  type  lo- 
cality: Total  length,  440.4  (410-465);  tail  vertebrae,  195  (185-210);  hind 
foot,  57.2  (55-60)  ;  ear  from  notch  (dry),  17.5,  18  (2  specimens).  Skull:  Aver- 
age of  9  adults  (5  males,  4  females)  from  type  locality:  Greatest  length,  56.3 
(54.8-58.5)  ;  Palatilar  length,  27  (26-28.5)  ;  zygomatic  breadth,  34.5  (33.1-35.7)  ; 
cranial  breadth,  23.5  (22.6-24.6)  ;  interorbital  breadth,  13  (12-14)  ;  postorbital 
constriction,  16  (15.1-17)  ;  length  of  nasals,  20.2  (19.1-21)  ;  maxillary  tooth  row, 
11.5  (11-12). 

Remarks. — Although  closely  related  to  C.  heecheyi.,  C.  atricapillus 
seems  to  be  a  distinct  species,  distinguished  by  darker  coloration 
of  the  head  and  anterior  back.  The  ranges  of  the  two  species  are 
apparently  separated  by  an  area  of  low  country  about  40  miles  in 
width,  where  squirrels  of  this  group  do  not  occur.  Furthermore, 
the  race  of  heecheyi  occurring  nearest  to  the  range  of  atricapillus  is 
very  much  paler  (less  blackish)  and  decidedly  smaller. 

Specimens  examined. — Total  number,  38,  as  follows: 
Baja  California:  Comondfl,  22;  San  Ignacio,  15;  **  San  Pablo,  11. 

NOTOCITELLUS,  subgenus  nov. 

[Characters  and  description  on  p.  44] 

Key  to  Species  and  Subspecies 

a^.  Cheeks  tawny. 

b\  Under  parts  darker annulatus   (p.  163) 

b'.  Under  parts  paler goldmani  (p.  164) 

a".  Cheeks  buffy adocetus  (p.  165) 

CITELLUS  ANNULATUS    (Axtoubon  and  Bachman) 
[Synonymy  under  subspecies] 

SpecifiG  characters. — Size  medium,  slightly  smaller  than  C.  heech- 
eyi heecheyi;  hind  foot,  50-&4  mm ;  tail,  186-228 ;  skull  length,  51.6- 
57.  Skull  similar  in  general  to  that  of  heecheyi.,  but  relatively  nar- 
rower across  the  zygomata,  which  are  less  widely  expanded  at  pos- 
terior end;  interorbital  breadth  relatively  greater;  upper  incisors 
shorter  and  thicker  (antero-posterior  diameter  greater). 

**  Eight  in  collection  San  Diego  Soc.  Nat.  Hist. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


163 


General  form  similar  to  that  of  G .  heecheyi  heecheyi  but  somewhat 
slenderer;  ears  broader  and  less  pointed;  feet  and  legs  slenderer; 
claws  on  front  feet  sharper  and  more  curved;  tail  nearly  or  quite  as 
long  as  the  body,  distichous,  rather  narrow,  and  not  bushy,  annulated 
with  about  15  blackish  bands. 


CITELLUS  ANNULATUS  ANNULATUS    (Aububon  and  Bachman) 

Ring-tailed  Geound  Sqihebel 

(Pis.  9;  26,  Z);  31,  Z)) 

Spermophilus  annulatus  Audubon  and  Bachman,  Jour.  Acad.  Nat.   Sci.  Phila. 

8:  319,  1842. 
Citellus  annulatus  Merriam,  Biol.  Soc.  Wash.  Proc.  16:  79,  1903. 
Otospermophilus  annulatus  Miller,  U.  S.  Natl.  Mus.  Bull.  128:  180,  1924. 

Type. — Not  designated  by  number;  the  type  specimen,  without  as- 
signed locality,  was  purchased  from  a  dealer  by  S.  F.  Baird  and 
presented   to  Audu- 


bon (Baird,  1857,  p 
327) ;  type  locality 
hereby  fixed  at 
Manzanillo,  Colima, 
Mexico. 

Range.  —  Colima 
and  northern  Guer- 
rero, Mexico;  prob- 
ably also  coastal  re- 
gion of  Michoacan 
(fig.  15).  Zonal 
range :  Entirely 
Tropical. 

Characters.  —  As 
given  under  specific 
characters.  Skulls 
of  females  average 
larger  than  those  of 
males. 

Color.  —  Upper 
parts,  including 
head,  nearly  uniform 
mixed  fuscous  black 
and  cinnamon  buff  or 
pale  pinkish  buff,  the 
blackish  color  often  predominating  on  the  head  and  sometimes  on 
portions  of  the  back;  chin,  throat,  and  sides  of  nose  and  face  ochra- 
ceous  buff;  sides  of  neck,  shoulders,  and  fore  limbs  hazel;  ears  and 
hind  legs  hazel  or  tawny ;  under  parts  warm  buff  or  pinkish  buff;  tail 
above,  mixed  pinkish  buff  and  black ;  tail  beneath,  hazel. 

Measurements. — Average  of  8  adult  males  from  Manzanillo,  Colima :  Total 
length,  439  (410-470)  ;  tail  vertebrae,  213.4  (187-228)  ;  bind  foot,  58  (54-64)  ; 
ear  from  notch  (dry),  14.0  (14-1(V).  Average  of  9  adult  females  from 
Manzanillo:  Total  length,  433.5  (390^70);  tail  vertebrae,  216.4  (193-238); 
hind  foot,  57.1  (54-60);  ear  from  notch  (dry),  15.4  (14-18).  Skull:  Average 
of  7  adult  males  from  Manzanillo:  Greatest  length,  53.6  (51.6-55.8)  ;  palatilar 
length,  25.2   (24-26.4)  ;  zygomatic  breadth,  30.5    (28.5-32.2)  ;  cranial  breadth, 


FiGUUK  15. — Distribution  of  the  subspecies  of  Citellus  an- 
nulatus: 1.  C.  a.  goldmani;  2,  O.  a.  annulatus. 


2g4  NORTH  AMERICAN  FAUNA  [No.  56 

21.8  (21.2-22.8)  ;  interorbital  breadth,  13.7  (13.3-15.2)  ;  postorbital  constric- 
tion, 14.4  (13.9-14.9)  ;  length  of  nasals,  17.8  (15.9-19.3)  ;  maxillary  tooth  row, 
10  (9.6-10.3).  Average  of  5  adult  females  from  ManzaniUo:  Greatest  length, 
55.4  (54^57)  ;  palatilar  length,  25.5  (25-26.2)  ;  zygomatic  breadth,  31.2  (30.4- 
32.6)  ;  cranial  breadth,  22.1  (21.1-23)  ;  interorbital  breadth,  14.5  (13.6-15.3)  ; 
postorbital  constriction,  14.3  (13.3-14.8)  ;  length  of  nasals,  18.3  (18-18.8)  ; 
maxillary  tooth  row,  9.9  (9.5-10.2). 

Remarks. — The  original  specimen  on  which  the  species  was  based 
was  purchased  from  a  dealer  and  was  supposed  to  have  come  from 
the  "western  prairies"  (Audubon  and  Bachman,  1851,  p.  215).  Baird 
(1857,  p.  327),  however,  considered  it  to  be  an  African  species,  of 
Sciurus  and  therefore  eliminated  it  from  the  list  of  North  American 
mammals.  Allen  (1877,  p.  886),  having  seen  a  skin  taken  by  Xantus 
on  the  plains  of  Colima,  restored  the  species  to  the  North  American 
list,  assuming  (in  the  absence  of  a  skull)  that  it  belonged  in  the 
subgenus  Otospermo'philus.  Both  Bachman  and  Allen  noted  the 
resemblance  of  this  animal  in  some  of  its  characters  to  the  tree 
squirrels  {Sciurus).  E.  W.  Nelson  and  E.  A.  Goldman,  on  their 
first  trip  to  Mexico  in  1892,  obtained  26  specimens  in  the  State  of 
Colima,  and  this  fine  series  has  provided  the  material  necessary  for 
the  present  study  of  the  species.  This  species  and  G.  adocetus  are 
the  only  ground  squirrels,  excepting  G.  insulai^s,  that  are  strictly 
tropical  in  their  range. 

The  original  description  differs  in  some  details  from  the  speci- 
mens in  hand.  Bachman  says :  "On  the  under  parts,  the  chin,  throat, 
belly,  and  inner  surface  of  the  legs  and  thighs  are  white",  whereas 
all  the  specimens  examined  have  these  parts  ochraceous  buff  or  warm 
buff,  except  that  in  a  few  the  belly  is  buffy  white. 

Specimens  examined. — Total  number,  30,  as  follows: 

Colima:  Armeria,  2;  Colima,  3;  Hacienda  San  Antonio  (at  base  of  Volcano  of 

Colima),  1;  ManzaniUo,  20. 
Guerrero:  El  Naranjo,  3;  La  Union,  1. 

CITELLUS  ANNULATUS  GOLDMANI  (Mebeiam) 

GrOiLDMAN'S   GrOTTND   SqUIBREL 

SpermopMlus  annulatus  goldmani  Merriam,  Biol.  Soc.  Wash.  Proc.  15:  69,  Mar. 

22,  1902. 
Citellus  annulatus  goldmani  Miller  and  Rehn,  Boston  Soc.  Nat.  Hist.  Proc.  31 : 

74,  1903. 
OtospermopMlus  annulatus  goldmani  Miller,  U.   S.  Natl.  Mus.  Bull.  128:  180, 

1924. 

Type. — Collected  at  Santiago,  Nayarit,  Mexico,  June  18,  1897,  by 
E,  W.  Nelson  and  E.  A.  Goldman;  female  adult,  skin  and  skull,  no. 
91259,  U.  S.  Natl.  Mus.  (Biological  Survey  collection)  (orig.  no. 
11223) . 

Range. — Known  at  present  only  from  the  southern  part  of  the 
State  of  Nayarit  on  the  west  coast  of  Mexico  (fig.  15).  Zonal  range: 
Tropical. 

External  characters. — Similar  to  typical  G.  a.  annulatus.,  but  hind 
foot  shorter;  upper  parts  averaging  darker  (more  blackish)  and 
under  parts  paler ;  tawny  color  on  sides  of  head  and  neck  paler  and 
less  extensive ;  hind  legs  less  tawny  and  more  mixed  with  blackish. 

Cranial  characters. — Skull  closely  similar  to  that  of  annulatus. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


165 


Color. — Upper  parts  fuscous  black,  sprinkled  with  ocliraceous 
buff ;  sides  of  head  and  neck,  and  fore  limbs  ocliraceous  tawny ;  sides 
of  body  warm  buff,  mixed  with  fuscous  black;  hind  limbs  tawny 
above,  the  thighs  mixed  with  fuscous  black;  throat  and  under  side 
of  hind  limbs  ocliraceous  buff ;  belly  pale  pinkish  buff ;  tail  beneath, 
tawny ;  above,  as  in  annulatus. 

Measurements. — Average  of  6  adult  females  from  Nayarit :  Total  length, 
415  (383-430)  ;  tail  vertebrae,  204  (186-216)  ;  bind  foot,  51.7  (50-54)  ;  ear 
from  notch,  15.2  (14.5-15.5).  Sktill:  Average  of  5  adult  females  from  Nayarit: 
Greatest  length,  53.5  (51.&-55.4)  ;  palatilar  length,  25  (24-26)  ;  zygomatic 
breadth,  30.4  (29-32.1)  ;  cranial  breadth,  22.2  (21.&-23.1)  ;  iuterorbital  breadth, 
13.5  (13-14.1)  ;  postorbital  constriction,  15.2  (14.5-15.8)  ;  length  of  nasals,  17.5 
(16.8-18.5)  ;  maxillary  tooth  row,  9.7  (9.3-10.1). 

Remarks. — Goldman's  ground  squirrel  is  a  slightly  darker  race  of 
C  annulatus,  occupying  an  area  to  the  northward  of  the  typical 
subspecies. 

Specimens  examined. — Total  number,  6,  as  follows : 

Nayarit:  Arroyo  de  Juan  Sanches  (about  40  miles  southwest  of  Compostela),  1; 
Compostela,  1 ;  San  Bias,  2 ;  Santiago,  2. 

CITELLUS  ADOCETUS  Mebeiam 

Lessee  Tbopical  Gbound  Sqtjibrel 

(Pis.  27,  E;  32,  E) 

Citellus  adocetus  Merriam,  Biol.  Soc.  Wash.  Proc.  16:  79,  May  29,  1903. 
Otospermophilus  adocetus  Miller,  U.  S.  Natl.  Mus.  Bull.  128 :  179,  1924. 

Type. — Collected  at  La  Salada,  40  miles  south  of  Uruapan,  Miclioa- 
can,  Mexico,  March  17,  1903,  by  E.  W.  Nelson  and  E.  A.  Goldman ; 

female    adult,    skin 

and  skull,  no.  126129, 
U.  S.  Natl.  Mus.  (Bi- 
ological Survey  col- 
lection) (orig.  no. 
16183). 

Range. — Southern 
Michoacan  and 
northern  Guerrero 
(fig.  16).  Zonal 
range :  Tropical. 

External  charac- 
ters.— Similar  to  C. 
annulatus  but  small- 
er and  paler  (less 
reddish) ;  tail  with- 
out annulations. 

Cranial  c  h  ar  ac- 
ters. — Skull    similar 
in  shape  and  denti- 
tion to  that  of  annulatus  but  much  smaller;  rostrum  shorter  and 
broader;  iuterorbital  region  relatively  broader;  variation  in  size  is 
considerable; -the  largest  skull  in  the  series  is  of  a  female. 

Color. — TF<97*n  pelage  (March)  :  Hairs  on  upper  parts  fuscous  at 
base,  tipped  with  pale  pinkish  buff  or  cream  color;  sides  of  head  and 


FionRE  16. — Distribution  of  Citellus  adocetus. 


IQQ  NORTH  AMERICAN  FAUNA  [No.  56 

neck  irregularly  blotched  with  ochraceous  tawny;  front  legs  pink- 
ish buff  or  cinnamon  buff;  hind  feet  cinnamon  buff,  the  thighs 
ochraceous  tawny;  tail  fuscous  or  fuscous  black,  mixed  with  pale 
pinkish  buff  or  buffy  white,  the  hairs  showing  three  dark  bands 
when  viewed  from  beneath,  but  without  annulations  above;  under 
side  of  tail  shaded  with  ochraceous  tawny  toward  the  tip;  under 
parts  pinkish  buff  or  warm  buff. 

Measurements. — ^Average  of  14  adults  (10  males,  4  females)  from  type  locality : 
Total  length,  335.3  (315-3,53)  ;  tail  vertebrae,  154.6  (138-168)  ;  hind  foot,  46.4 
(43^8)  ;  ear  from  notch,  14  (13-15).  Skull:  Average  of  11  adults  and  subadults 
(6  males,  5  females)  :  Greatest  length,  43.6  (41.6-46.2)  ;  palatilar  length,  20.4 
(19-22)  ;  zygomatic  breadth,  24.6  (23.1-26.2)  ;  cranial  breadth,  19.2  (18.3-20.1)  ; 
interorbital  breadth,  11.9  (11.5-13.8)  ;  postorbital  contriction,  13.4  (12.6-14.3)  ; 
length  of  nasals,  13.5  (11.1-14.7)  ;  maxillary  tooth  row,  8.7  (7.7-9.2). 

Remarks. — This  ground  squirrel,  although  clearly  rather  closely 
related  to  annulatus,  differs  from  it  in  many  important  characters 
of  both  skin  and  skull.  It  occupies  a  somewhat  more  arid  district, 
farther  from  the  coast  than  does  annulatus.  The  ranges  of  the  two 
nearly  meet  and  possibly  overlap  in  northern  Guerrero.  Like  an- 
nulatus., the  range  of  this  species  is  entirely  within  the  Tropics. 

Specimens  examined. — Total  number,  36,  as  follows : 

Guerrero:  La  Escondida  (about  20  miles  southeast  of  Balsas),  1. 
Michoacan:  La  Huacana,  2;  La  Salada,  32 ;  Volcan  JaruUo,  1. 

Subgenus  AMMOSPERMOPHILUS  Merriam 

[Cranial  characters  on  p.  44] 
EXTERNAL  CHARACTERS 

Upper  parts  nearly  uniform,  varying  from  pinkish  buff,  vinaceous 
buff,  pinkish  cinnamon,  or  vinaceous  cinnamon,  to  wood  brown,  army 
brown,  fawn,  drab  gray,  or  mouse  gray ;  a  narrow,  white  longitudinal 
line  on  each  side  of  the  back,  from  the  shoulders  to  the  rump;  tail 
above,  mixed  black  and  white,  similar  beneath,  or  with  a  broad  white 
or  buffy  median  area. 

PELAGE  AND  MOLT 

The  winter  pelage  is  dense  and  soft,  the  summer  pelage  shorter 
and  more  wiry.  The  bases  of  the  hairs  are  plumbeous,  succeeded  by 
a  rather  broad  whitish  or  buffy  area,  then  a  narrow  brownish  area, 
and  tipped  with  white,  or  varying  shades  of  buff,  cinnamon,  and  gray. 

The  squirrels  of  this  group  have  two  molts  annually;  the  spring 
molt  takes  place  between  the  middle  of  April  and  early  July — usually 
in  May  or  June — and  begins  ordinarily  on  the  head  and  shoulders, 
but  sometimes  in  patches  all  over  the  back.  The  fall  molt  occurs 
from  about  the  middle  of  September  to  the  last  of  October,  and  pro- 
ceeds from  the  rump  and  flanks  forward.  Several  specimens  of  Citel- 
lus  leuxiurus  peninsulae  from  Baja  California  are  unusual  in  having 
a  fresh  pelage  coming  in  on  the  hinder  parts,  between  August  8 
and  23. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  167 

Ket  to  Species  and  Subspecies 

o.*  Under  side  of  tail  with  median  area  white. 
J)}  Tail  hairs  with  two  black  bauds. 

c.^  Upper  parts  more  buffy  (pinkish  buff  to  wood  brown) nelsoni  (p.  182) 

c/  Upper  parts  less  buffy  (vinaceous  cinnamon  to  army  brown 
or  drab  gray). 

d.^  Upper  parts  drab  gray interpres  (p.  180) 

d.'  Upper  parts  not  drab  gray. 

e.^  Anterior  upper  premolar  absent  or  rudimentary-  insularis   (p.  181) 
e.^  Anterior  upper  premolar  present. 

f.^  Smaller  and  paler canfieldae  (p.  178) 

f.^  Larger  and  darker. 

g}  Rump  and  thighs  army  brown penhnulae  (p.  176) 

g?  Rump  and  thighs  vinaceous  cinuamon cxtimus  (p.  179) 

6.^  Tail  hairs  with  one  black  band, 
c*  General  tone  of  upper  parts  vinaceous  cinnamon. 

d.^  Upper  parts  light  vinaceous  cinnamon pennipcs   (p.  175) 

d.^  Upper  parts  vinaceous  cinnamon. 

e.^  Back   darkened  with   fuscous tersus   (p.  173) 

e.^  Back  not  darkened  with  fuscous cinnamomeus  (p.  174) 

c.^  General  tone  of  upper  parts  pinkish  buff leucurus   (p.  170) 

a.^  Under  side  of  tail  without  median  white  area. 

&.*  Colors   darker han-isH  (p.  167) 

6.*  Colors  paler saxicola  (p.  169) 

CITELLUS  HARRISII    (Audubon  and  Bachman) 
[Synonymy  under  subspecies] 

Specific  characters. — Size  about  as  in  the  larger  races  of  0.  leucurus^ 
but  tail  averaging  longer,  74-91  mm;  hind  foot,  38-42;  skull  length, 
38.2^1.2.  Skull  closely  similar  to  that  of  C.  leucurus  cinnamomeus. 
Upper  parts  in  summer  pinkish  cinnamon,  more  or  less  darkened  with 
fuscous;  in  winter,  mouse  gray;  tail  above  and  below,  mixed  black 
and  white  (lacking  the  clear  white  under  surface  of  leucurus). 

CITELLUS  HARRISII  HARRISII  (Audubon  and  Bachman) 

Gray-tailed  Antelope  Squirrel 

(PI.  10) 

Spermophilus  harrisii  Audubon  and  Bachman,  Quad.  North  Amer.  3 :  267,  1854. 

Tamias  harrisi  Merriam,  North  Amer.  Fauna  2 :  19,  1889. 

Anisonyx  {Ammospermophilus)   harrisii  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  7: 

240,  1895. 
[Citellus]  harrisi  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  4 :  141, 1904. 
Ammospermophilus  harrisii  Moarns,  U.  S.  Natl.  Mus.  Bull.  56 :  303,  1907. 

Type. — None  designated;  description  based  on  a  specimen  presented 
lo  Audubon  by  Edward  Harris,  supposed  to  have  been  collected  by 
John  K.  Townsend,  but  locality  unknown.  The  type  locality  is  hereby 
fixed  in  the  Santa  Cruz  Valley,  Ariz.,  at  the  Mexican  boundary  line.^^^ 

Range. — Greater  part  of  southern,  central,  and  northwestern  Ari- 
zona; north  to  the  Colorado  liiver,  west  of  longitude  113°;  east  to 
southwestern  New  Mexico  (Hidalgo  County)  ;  south  to  southern 
Sonora  (Ortiz) ;  west  to  Quitobaquito,  on  the  Mexican  boundary  line 
(fig.  17).    Zonal  range:  Lower  Sonoran. 

"«» Meains  (1896,  p.  444),  in  (Inscribing  the  subspecies  saxicola,  restricted  the  name 
harrisii  "to  the  darljcr  form,  which  was  found  in  the  Elevated  Central  Tract,  along 
the  .Mexican  boundary  line,  from  the  Santa  Cruz  Valley  westward  as  far  as  Uw 
Sonoyta     *     ♦     *." 


168 


NORTH  AMERICAN  FAUNA 


INo.  56 


External  characters. — Similar  to  G.  leucurus  leucurus  but  larger  and 
slightly  darker;  tail  longer  and  darker,  the  under  surface  mixed 
black  and  white  (never  clear  white).  Compared  with  G.  I.  cinna- 
TTbomeus:  Coloration  in  winter  pelage  much  more  grayish  (less  vina- 
ceous) ;  in  summer  pelage  darker  and  less  vinaceous;  tail  longer  and 
darker  beneath. 

Granial  characters. — Skull  similar  to  that  of  leucurus  and  of  cin- 
namoTneus,  but  averaging  larger. 

Golor. — Winter  pelage:  General  tone  of  upper  parts  mouse  gray, 
the  hairs  fuscous  subterminally,  conspicuously  tipped  with  white; 
head  and  face  vinaceous  buff  or  fawn  color;  shoulders  and  thighs 

vinaceous  fawn; 
front  legs  and  feet 
vinaceous  cinnamon; 
hind  feet  light  vina- 
ceous cinnamon,  the 
toes  pinkish  buff; 
tail  above  and  below, 
mixed  black  and 
white,  the  hairs  with 
a  broad  subterminal 
band  of  black  and  a 
narrower  black  band 
near  the  base.  Sum- 
mer pelage:  Upper 
parts  nearly  uniform 
light  pinkish  cinna- 
mon, clearest  on  the 
shoulders  and  thighs, 
somewhat  darkened 
with  fuscous  on  the 
back. 

Molt. — The  spring 
molt  occurs  in  May; 
specimens  taken  May 
13,  16,  and  19,  re- 
spectively, are  in 
badly  worn  condi- 
tion, with  new  hair 
occurring  in  patches 
all  over  the  body. 
Measurements. — Average  of  12  adults  (9  males,  3  females)  from  Tucson  and 
Oracle,  Ariz. :  Total  length,  233.8  (225-250)  ;  tail  vertebrae,  82.7  (74^94)  ;  hind 
foot,  39.7  (38-42).  Skull:  Average  of  8  adult  males  from  Tucson  and  Santa 
Rita  Mountains:  Greatest  length,  40  (38.8-41.2)  ;  palatilar  length,  18.3  (17-19)  ; 
zygomatic  breadth,  23.4  (22.8-24.7)  ;  cranial  breadth,  19.1  (18.6-19.5)  ;  interor- 
bital  breadth,  9.9  (9-10.8)  ;  postorbital  constriction,  14.4  (13.9-14.9)  ;  length  of 
nasals,  13.1  (12-13.5)  ;  maxillary  tooth  row,  7.2  (6.8-7.5).  Average  of  7  adult 
females  from  Tucson,  Phoenix,  and  Roosevelt  Lake :  Greatest  length,  39.4 
(38.4-39.9)  ;  palatilar  length,  18.1  (18-18.5)  ;  zygomatic  breadth,  23  (22.1-23.7)  ; 
cranial  breadth,  19  (18.5-19.8)  ;  interorbital  breadth,  9.8  (9.4-10.5)  ;  postor- 
bital constriction,  13.7  (13.1-14.5)  ;  length  of  nasals,  12  (11.5-12.7)  ;  maxillary 
tooth   rovr,   7.4    (7-7.8). 

Weight. — Three  specimens  weighed,  respectively,  112,  122,  and  139  g. 


Figure  17. — Distribution  of  Citellus  interpres,  C.  in^ularis, 
and  C.  nelsoni  and  of  the  subspecies  of  G.  leucurus  and 
C.  harrisii  (subgenus  AvimospermopMlvs)  :  1,  C.  I.  leucu- 
rus; 2,  C.  I.  pennipes ;  3,  G.  I.  cinnamomeus ;  4,  G.  I. 
tersus;  5,  G.  I.  peninsulae;  6,  C.  I.  canfleldae ;  7,  G.  I.  ex- 
timus;  8,  G.  insularis;  9,  G.  h.  samicola;  10,  G.  h.  harrisii; 
11,  G.  interpres;  12,  C.  nelsoni. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  IgQ 

Remarks. — Described  by  Audubon  and  Bachman  in  1854,  this  re- 
mained the  only  recognized  species  of  the  group  until  1889,  when 
Merriam  separated  leucurus^  which  up  to  that  time  had  been  con- 
fused with  harrisii.  It  seems  remarkable  that  a  species  so  distinct 
as  this  should  occupy  an  area  in  the  middle  of  the  range  of  the 
group,  and  separated  from  its  congeners  by  no  seemingly  effective 
barriers,  at  least  to  the  eastward.  No  reason  is  apparent  why  either 
harrisii  or  0.  interpres  should  not  occupy  southwestern  New  Mexico, 
but  so  far  as  known,  there  is  a  considerable  gap  in  that  region  between 
the  ranges  of  these  two  species.  On  the  west  and  north,  the  Colorado 
River  with  its  deep  canyon  has  proved  to  be  effective  in  separating 
the  ranges  of  harrisii  and  leucurus. 

Specimens  examined. — Total  number  217,  as  follows : 

Arizona:  Baboquivari  Mountains,  1;  Beale  Spring  (near  Kingman),  6;  Big 
Sandy  Creek  (Moliave  County),  5;  Camp  Verde  (Yavapai  County),  16; 
Congress  Junction,  7;  Coyote  Mountains  (Pima  County),  1;  Dolan  Spring 
(12  miles  nortliwest  of  Chloride),  14;  Fish  Creek  (Maricopa  County),  4; 
Fort  Bowie,  9;  Fort  Mohave,  5;  Gila  Mountains  (Graham  County),  2; 
Graham  Mountains  (Pinaleno  Range),  1;  Gold  Basin  (Mohave  County),  3; 
Gold  Road  (Mohave  County),  3  ;  **  Hackberry  (Mohave  County),  1 ;  Harqua- 
hala  Mountains,  1;  H-Bar  Ranch  (Gila  County,  10  miles  south  of  Payson), 
2;  Indian  Oasis  (Pima  County),  1;  Kingman,  3;'°  Kirkland  (Yavapai 
County),  4;  Klondyke  (Graham  County),  2;  La  Oso  (Pima  County),  1; 
Little  Meadows  (east  side  Black  Mountains,  Mohave  County),  6;  Mammoth 
(Pinal  County),  1;  Maricopa  County  (20  miles  southwest  of  Phoenix),  2;" 
McMillenville  (Gila  County),  1;  Mineral  Park  (Mohave  County),  4;  Monte- 
zuma Well  (Yavapai  County),  4;  Mud  Spring  (18  miles  northwest  of  King- 
man), 7;  New  River  (Maricopa  County),  4;  Oatman,  1;'"  Old  Searchlight 
Ferry,  Colorado  River,  1 ;  Oracle  (Pinal  County),  15  ;  Peach  Springs  (Mohave 
County),  3;  Phoenix,  7;  Pima  County  (30  miles  south  of  Tucson),  14;'^ 
Quitobaquito  (Pima  County),  5;  Rice  (Gila  County),  1;  Roosevelt  (17  miles 
east),  1;  Roosevelt  Lake,  3;  Salt  River  (12  miles  north  of  McMillenville),  1; 
Salt  River  Mountains,  2;'^  Santa  Catalina  Mountains  (mouth  of  Bear  Can- 
yon), 2;  Santa  Rita  Mountains  (north  base),  4;  Sheldon  (Greenlee  County), 
2;  Superior,  2;  Tucson,  16;  Turkey  Creek  (east  base  of  Bradshaw  Moun- 
tains, Yavapai  County),  5;  Vail  (Pima  County),  2;®°  Vulture  (20  miles 
southwest  of  Wickenburg),  1;  Wickenburg,  1. 

New  Mexico:  Animas  (12  miles  northwest,  Grant  County),  1. 

Sonora:  Hermosillo,  1;  Magdalena,  3;  Ortiz,  1;  Poso  de  Luis  (5  miles  south  of 
Monument  152),  1. 

CITELLUS  HARRISII  SAXICOLA    (Meabns) 
Yuma  Antbxopb  Sqihrrel 

Spermophilus  harrisii  saxicolus  Mearns,  U.  S.  Natl.  Mus.  Proc.  18 :  444,  May  28, 

1896  (advance  sheet  published  March  25,  1896). 
iCitellus    (Spermophilus)    harrisi]    saxicola  Elliot,   Field  Columb.    Mus.   Pub., 

Zool.  Ser.  4:  142,  1904. 
Ammospermophilus  harrisii  saxicola  (Mearns),  U.  S.  Natl.  Mus.  Bull.  5^^  fe- 

1907.  ,  length, 

Ammospermophilus  harrisii  kinoensis  Huey,  San  Die.';;,-;  ;'  v.iiiiliEJT'<9*'eadth,  18.4 

352,  1937  (Bahia  Kino,  Sonora,  Mexico).       ,   postorbital  constriction,   13.9 

7'y^^e._Collected  at  T'  -  •---'  '  maxillary  tooth  row,  6.7  (6.1-7). 

Ariz.,  February  16,  18iTy  extensive  rancre  this  race  shows  relativelv 

and  skull,  no.  59869,  Us  from  southeastern  Oregon  appears  slightly 

'rom  the  type  region,  but  the  differences  are 

7oii'n7*'''lV'^u^^"^-  ^/^^-  "'^V-n  by  name.     Intergradation  with  C.  I.  cinna- 

'"  Univ.  Michigan  Mus.  S5oo'  A  ,  tt,    ii^i  t  j.  j.        js 

"Kansa.s  Univ.  Mus.  Nafi  Southwestern  Utah  and  the  adjacent  parts  or 

«  Field  MU.S.  Nat.  iiist3  of  eight  specimens  from  St.  George,  Utah,  some 

are  like  typical  leucurus  and  others  almost  like 


170  NORTH  AMERICAN  FAUNA  •  [No.  56 

Range. — Southwestern  Arizona  and  northwestern  Sonora,  from  the 
Colorado  River  east  to  about  longitude  113°  (fig.  17).  Zonal  range: 
Lower  Sonoran. 

External  characters. — Closely  similar  to  G.  h.  harrisii  but  averag- 
ing paler  on  the  head,  back,  shoulders,  and  thighs. 

Cranial  characters. — Skull  very  similar  to  that  of  harrisii  but 
averaging  slightly  smaller. 

Color. — Winter  pelage:  General  tone  of  upper  parts  smoke  gray, 
varying  to  light  cinnamon  drab,  the  hairs  conspicuously  tipped  with 
white ;  head,  face,  shoulders,  and  thighs  vinaceoiis  buff ;  otherwise  as 
in  harrisii.  Summer  pelage:  General  tone  of  upper  parts  vinaceous 
fawn,  somewhat  darkened  by  the  fuscous  bases  of  the  hairs,  the 
white  tips  mostly  worn  off. 

Measurements. — Average  of  11  adults  (6  males,  5  females)  from  type  lo- 
cality: Total  length,  234  (222-245);  tail  vertebrae,  86.2  (81-92);  Mnd  foot, 
39.3  (38-41).  Skull:  Average  of  12  adults  (8  males,  4  females)  from  type  lo- 
cality: Greatest  length,  39.4  (38.2-40.3);  palatilar  length,  17.8  (16.5-18.8); 
zygomatic  breadth,  23  (22.3-23.6)  ;  cranial  breadth,  18.9  (18.6-19.3)  ;  interor- 
bital  breadth,  9.6  (9.1-10.7)  ;  postorbital  constriction,  13.7  (12.4-14.2) ;  length  of 
nasals,  12.4  (11.3-13.8)  ;  maxillary  tooth  row,  6.9  (6.6-7.5). 

Specimens  examined. — Total  number  65,  as  follows: 

Arizona:  Ajo  (10  miles  north,  Pima  County),  6;  Castle  Dome  (Yuma  County), 
2;  Gila  Mountains  (Yuma  County),  1;  Granite  Mountains  (near  Monu- 
ment 187),  2;  Parker  (Yuma  County),  5;  Quartzsite  (Yuma  County),  1; 
Tinajas  Altas  (Yuma  County),  15;  Tule  Wells  (Yuma  County),  3;  Vicks- 
burg  (Yuma  County),  6;  Yuma,  12. 

Sonora:  Bahia  Kino,  6; '""  Porto  Libertad,  6."'* 

CITELLUS  LEUCURUS  (Meeeiam) 
[Synonymy  under  subspecies] 

Specific  characters. — Size  of  C.  harrisii  or  somewhat  smaller ;  hind 
foot,  85-43  mm;  tail,  54-87;  skull  length,  37-41.8.  Skull  essentially 
like  that  of  harrisii^  but  smaller  in  some  races.  General  tone  of  upper 
parts  varying  in  summer  pelage  from  pinkish  cinnamon  or  vinaceous 
cinnamon  to  cinnamon  drab,  fawn  color,  or  army  brown,  the  hairs 
more  or  less  tipped  with  white  or  buffy  white ;  in  winter  pelage  more 
grayish,  drab  gray  or  mouse  gray;  tail  broadly  white  or  whitish 
below,  bordered  with  fuscous  black. 

CITELLUS  LEUCURUS  LEUCURUS   (Mebeiam) 

White-tailed  Antelope  Sqtjibeel 

(Pis.  10;  27,  F;  32,  E) 

^^^^^'^(iDMlus  harrisii  Baird,  Mamm.  North  Amer.,  p.  313,  1857  (not  of  Audubon 

^?om"rtS''l""(ii8-North  Amer.  Rodentia.  p.  810,  1877  (not  Spenno- 
bital  breadth,  9.9  (9-10.8)  ;  postorbi&fi'ei^-^^.i.ctxoi  . 
nasals,  13.1  (12-13.5)  ;  maxillary  tooth  rov?,  7.2  (6";^i°^y-    „_    ^g„„ 
females   from   Tucson,   Phoenix,   and   Roosevelt   L,    r  «  *    VJ .  oVn ' -lono 
(38.4-39.9)  ;  palatilar  length,  18.1  (18-18.5)  ;  zygom^,^-  ^e^.  ^^±^%f^J|i    -.qos 
cranial   breadth,   19   (18.5-19.8);   interorbital   brea  "b.,  Zooi.  Ser.  d.  ^41,  lyud 
bital  constriction    13.7   (13.1-14.5)  ;  length  of  nasah  ^ 
tooth   row,   7.4    (7-7.8).  -  ' 

Weight. — Three  specimens  weighed,  respectively.  111,. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  17X 

Type. — Collected  in  San  Gorgonio  Pass,  Kiverside  County,  Calif., 
May  16,  1885,  by  Frank  Stephens;  male  adult,  skin  and  skull,  no. 
186466,  U.  S.  Natl.  Mus.  (-Hif ,  Merriam  collection)   (orig.  no.  68). 

Range. — Desert  regions  of  southeastern  Oregon,  southwestern 
Idaho,  Nevada,  western  Utah,  southeastern  California,  and  north- 
eastern Baja  California;  north  to  northern  Malheur  County,  Oreg., 
and  the  Snake  Kiver  Valley,  Idaho ;  east  to  the  Sevier  Eiver  Valley, 
Utah;  south  to  San  Felipe  Bay,  Baja  California;  west  to  the  Mohave 
Desert,  Calif,  (fig.  17).    Zonal  range:  Upper  and  Lower  Sonoran. 

External  characters. — Similar  in  color  to  O.  harrisii  harrisii  but 
upper  parts  and  limbs  paler,  especially  in  winter  pelage ;  tail  shorter 
and  pure  white  instead  of  grizzled  gray  beneath. 

Cranial  characters. — Skull  closely  similar  to  that  of  harrisii  but 
averaging  slightly  smaller. 

Color. — Summer  pelage:  Head  and  upper  parts  vinaceous  buff; 
eye  ring  and  lateral  stripes  white ;  front  and  hind  limbs  light  pinkish 
cinnamon,  shading  to  buffy  white  on  the  feet ;  tail  above,  mixed  black 
and  white,  except  at  the  base,  where  it  is  like  the  body  color;  tail 
beneath,  clear  creamy  white,  with  a  subterminal  band  of  black  on  the 
-sides  and  tip;  under  parts  white  or  buffy  white.  'Winter  pelage 
(November)  :  Hairs  on  median  dorsal  area  white  at  the  tips,  with  a 
subterminal  band  of  fuscous,  producing  the  general  tone  effect  of 
drab  gray  or  pale  drab  gray,  shading  to  vinaceous  buff  on  the  head 
and  fore  legs ;  hind  legs  vinaceous  cinnamon. 

Molt. — The  spring  molt  may  begin  as  early  as  the  middle  of  April 
or  be  deferred  until  July.  A  specimen  taken  in  the  Panamint  Moun- 
tains, Calif.,  April  16,  is  in  much  worn  pelage,  but  shows  new  pelage 
coming  in  on  the  head  and  fore  back ;  one  from  Granite  Creek,  Nev., 
May  18,  is  in  a  similar  condition  of  molt;  two  specimens  from 
Cabazon,  Calif.,  May  30  and  June  2,  show  fresh  pelage  appearing  in 
patches  all  over  the  upper  parts  from  nose  to  root  of  tail.  A  female 
from  Walker  Pass,  Calif.,  June  21,  had  just  be^un  to  molt  on  the 
head  and  fore  back;  a  badly  worn  female  specmien  from  the  San 
Jacinto  Mountains,  Calif.,  July  6,  shows  new  hair  coming  in  in 
patches  all  over  the  body.  The  fall  molt  takes  place  in  September 
or  October,  commencing  on  the  tail  and  hinder  part  of  body ;  a  speci- 
men from  Whitewater,  Calif.,  September  13,  shows  new  winter  pelage 
covering  the  posterior  half  of  the  body;  one  from  Antelope  Valley, 
Los  Angeles  County,  Calif.,  October  17,  had  completed  the  fall  molt 
except  on  the  head. 

Measuretnents. — Average  of  10  adults  (5  males,  5  females)  from  type  locality: 
Total  length,  216.3  (211-22.3)  ;  tail  vetebrae,  67.5  (^3-71)  ;  hind  foot,  38.3  (37- 
40)  ;  ear  from  notch,  9  (8.5-10).  Skull:  Average  of  11  adults  (8  males,  3  fe- 
males) from  type  locality:  Greatest  length,  3S.S  (.37.3^0);  palatilar  length, 
17.6  (16.8-18.5)  ;  zygomatic  breadth,  22.6  (21.7-23.5)  ;  cranial  breadth,  18.4 
(17.8-19.3)  ;  interorbital  breadth,  9.7  (8.8-10.4)  ;  postorbital  constriction,  13.9 
(13.1-14.9)  ;  length  of  nasals,  11.4  (10.7-12)  ;  maxillary  tooth  row,  6.7  (6.1-7). 

Remarks. — Over  its  very  extensive  rancre  this  race  shows  relativelv 
little  variation.  A  series  from  southeastern  Oregon  appears  slightly 
darker  than  the  series  from  the  type  region,  but  the  differences  are 
too  slight  for  recognition  by  name.  Intergradation  with  C.  I.  cinna- 
m,omeus  takes  place  in  soutJiwestern  Utah  and  the  adjacent  parts  of 
Arizona.  In  a  series  of  eight  specimens  from  St.  George,  Utah,  some 
of  the  specimens  are  like  typical  leucurus  and  others  almost  like 


l'J2  NORTH  AMERICAN  FAUNA  [No.  56 

typical  cinnamomeus.  One  from  Canaan  Spring,  Utah,  agrees  in 
color  with  leucurus,  but  has  a  large  skull  like  that  of  cinnamomeus. 

This  species  was  confused  with  harrisii  by  all  writers  prior  to  1889, 
when  Merriam  pointed  out  its  characters  and  named  it. 

Specimens  examined. — Total  number,  584,  as  follows: 

Arizona:  Beaverdam  ( =Littlefiel(l,  Mohave  County),  1;  Grand  Wash  (8  miles 
south  of  Pakoon  Spring,  Mohave  County),  2;  Wolf  Hole  (6  miles  north, 
Mohave  County),  2. 

Baja  California:  San  Felipe,  IS;''""  San  Felipe  Bay,  1;  San  Pedro  Martir 
Mountains,  4. 

California:  Amedee  (Lassen  County),  1;  Antelope  Valley  (Los  Angeles  County), 
1;  Argus  Mountains,  6;  Banning,  4;  Barstow,  17;  Beckvpith  Pass  (Lassen 
County),  2;  Benton  (Mono  County),  1;"  Bergmann's  (25  miles  east  of 
Temecula,  Riverside  County),  1;''*  Bishop  (8  miles  west),  1;  Borax  Flat 
( San  Bernardino  County),  3;  Cabazon  (Riverside  County),  29;  Chucka walla 
Spring  (Riverside  County),  1;  Coast  Range  Mountains  (east  base,  5  miles 
north  of  Monument  no.  230),  7;  Colorado  Desert,  1;  Colorado  River  (oppo- 
site Parker,  Ariz.),  5;  Coso  (Inyo  County),  13;  Coso  Mountains,  2;'"  Dag- 
gett (San  Bernardino  County),  1;  Darwin  (Inyo  County),  1;"  Deep  Spring 
Valley  (Inyo  County),  1;  Emigrant  Spring,  Panamint  Mountains,  1; 
Funeral  Mountains,  1 ;  Furnace  Creek  Ranch,  Death  Valley,  1 ;  Goffs  ( San 
Bernardino  County),  6;  Granite  Wells,  Mohave  Desert,  2;  Hesperia  (San 
Bernardino  County),  1;  Hodge  (San  Bernardino  County),  1;  Independence 
(Inyo  County),  1:^*  Inyo  Mountains,  7;"'^  Ivanpah  (San  Bernardino 
County),  4;  Jacumba  (San  Diego  County),  1;  Kearsarge  Pass,  1;'^  Keeler, 
6;  ■''"Kern  River  Valley  (near  Kernville),  1;  Little  Lake  (Inyo  County), 
1 ;"  Little  Owens  Lake,  1 ;  Lone  Pine,  8 ;  Lone  Willow  Spring  ( San  Bernar- 
dino County),  9;  Long  Valley  (Lassen  County),  1;  Lower  Alkali  Lake 
(Modoc  County),  2;  Ludlow  (San  Bernardino  County),  2;  Mohave,  26; 
Mohave  Desert,  7;  Mountain  Spring  (4  miles  north  of  Monument  no.  231, 
San  Diego  County),  14;  Needles,  11;  Onyx  (Kern  County),  20;  Oro  Grande 
(San  Bernardino  County),  10;  Owens  Valley,  6;  Owens  Lake,  5;  Palm 
Springs,  5;  Panamint  Mountains,  42;  Panamint  Valley,  4;  Providence 
Mountains,  3;  Radec  (12  miles  east  of  Temecula,  Riverside  County),  5; 
Resting  Springs  (Inyo  County),  15;  Saline  Valley  (Inyo  County),  1;  Salt 
Wells  Valley  (Death  Valley),  2;  San  Felipe  River  (San  Diego  County), 
4 ;  San  Felipe  Canyon,  1 ;  San  Gorgonio  Pass,  7 ;  San  Jacinto  Mountains 
(Oak  Valley),  1;  Secret  Valley  (Lassen  County),  2;  Shoshone  (Inyo 
County),  1;"  Smoke  Creek  (at  head,  Lassen  County),  1;  Twelve  Mile 
Spring  (12  miles  north  of  Resting  Springs),  1;  Vallecito  (San  Diego 
County),  2;  Victorville,  3;  Walker  Pass  (Kern  County),  4;  Weldon  (Kern 
Coimty),  1;"  Whitewater  (Riverside  County),  4. 

Idaho :  Glenns  Ferry,  2 ;  Murphy,  1. 

Nevada:  Alamo,  Lincoln  County,  1;'^  Ash  Spring  (Pahranagat  Valley),  2;'"  Ash 
Meadows  (Nye  County),  IS;  Baker  Creek  (White  Pine  County),  2;'^^  Black 
Canyon,  Colorado  River,  3;  Blair  (Esmeralda  County),  1;  Candelaria,  5;''* 
Carson  City,  1;  Cedar  Basin  (Clark  County),  2;^  Charleston  Mountains,  4; 
Cloverdale  (6  miles  south  of  Golden,  Nye  County),  2;  Desert  Valley  (23 
miles  west  of  Panaca,  Lincoln  County),  1;"  Elko  County,  8  miles  south  of 
Wendover,  Utah,  1;"  Esmeralda  County,  2;™  Flowing  Springs  (Humboldt 
County),  2;  Granite  Creek  (Washoe  County),  7;  Grapevine  Mountains,  1; 
Groom  Baldy  (16  miles  east,  Lincoln  County),  2;"  Hot  Creek  Range  (Nye 
County).  1;"  Hot  Creek  Valley  (Twin  Spring),  1;^*  Imlay,  2;  Lehmain 
Cave  (White  Pine  County),  1;^^  Little  High  Rock  Canyon  (Washoe  County), 
1;"  Lund  (White  Pine  County),  1:"  Meadow  Vallev  (24  miles  south  of 
Caliente),  1;''  Millette,  3;""  Nyala  (Nye  County),  1;"  Oasis  Valley  (Nye 
County),  6;  Osobb  Valley  (Churchill  County),  1;  Pahranagat  Mountains 
(Lincoln  County),  1;  Pahranagat  Valley,  5;"  Pahroc  Spring  (Lincoln 
County).  1;  Pahrump  Valley  (Nye  County),  10;  Pyramid  Lake,  14;  Quinn 

■^^Mus.  Vert.  Zool. 

''*'  J.  H.  Fleming  collection. 

's  Field  Mus.  Nat.  Hist. 

''^Kansas  Univ.  Mus. 

™  San  Diego  Soc.  Nat.  Hist. 

««  California  Inst.  Tech. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  173 

Canyon  Mountains,  1 ;"  Raspberry  Creek  (near  Cosgrave,  Pershing  County), 
1;  Reese  River  (Nye  County),  1;  St.  Thomas,  1;*"  Sharp  (Nye  County),  4;" 
Silver  Peak  Mountains,  4;  Spring  Valley  (White  Pine  County),  2;'"  Thorp 
Mill  (east  base  Grapevine  Mountains),  2;  Timpahute  Mountains,  1;  Virgin 
Valley  (Humboldt  County),  1;'^  Virginia  Mountains,  2;  Vegas  Valley  (Lin- 
coln County),  3;  Wadsworth,  6;  Washoe  Lake,  1;  White  River  Valley  (Nye 
County ) ,  1  ;'^  Winnemucca  Lake,  10. 

Oregon:  Adel  (Lake  County),  4;  Rome  (Malheur  County),  1;  South  Warner 
Lake,  1;  Tumtum  Lake,  6;  Vale,  1;  Warner  Valley,  1;  Watson  (Malheur 
County),  10. 

Utah:  Canaan  Spring  (Washington  County,  near  Arizona  line),  1;  Clear  Creek 
(Sevier  County),  1;  Elberta  (Utah  County),  2;^"  Esealante,  1;™^  Fillmore, 
1;  Hebron  (Washington  County),  4;  Junction  (Piute  County),  1;  Marysvale, 
2;  Monroe,  2;"  Nephi,  1;  Parowan,  1;''*  Promontory  Point  (Box  Elder 
County),  1;  St.  George,  9;  Sevier  River  (10  miles  south  of  Panguitch),  1; 
Toquerville,  2. 

CITELLUS  LEUCURUS  TERSUS    (Goldman) 

Gband  Canyon  Antexope  Squirrel 

AmmospermophUns  Jeiicurus  tersus  Goldman,  Jour.  Wash.  Acad.  Sci.  19:  435, 
Nov.  19,  1929. 

Type. — Collected  in  Prospect  Valley,  Grand  Canyon,  Hiialpai  In- 
dian Reservation,  Ariz,  (4,500  feet  altitude) ,  October  3, 1913,  by  E,  A. 
Goldman ;  male  subadult,  skin  and  skull,  no.  202645,  U.  S.  Natl.  Mus. 
(Biological  Survey  collection)  (orig.  no.  22269). 

Range. — Terraces  on  southern  side  of  Grand  Canyon,  in  the  Hual- 
pai  Indian  Reservation,  Ariz.  (fig.  17).  Zonal  Range:  Upper 
Sonoran. 

External  characters. — Similar  in  size  to  C.  I.  leucunts,  but  upper 
parts  darker  (more  brownish,  less  grayish),  especially  on  the  rump 
and  lower  back.  Compared  with  C.  I.  cinnamomeiis:  Upper  parts 
more  brownish  (less  pinkish  or  cinnamon) ;  size  smaller. 

Cranial  characters. — Skull  similar  to  that  of  leucurus.,  but  averag- 
ing slightly  smaller  in  length  and  zygomatic  breadth;  nasals  about 
same  length,  but  slightly  narrower. 

Color. — Winter  pelage:  Upper  parts  fawn  color  or  army  brown; 
shoulders  and  fore  back  heavily  sprinkled  with  whitish  hairs;  hinder 
back,  rump,  and  thighs  darker;  feet  whitish,  washed  with  light  vina- 
ceous  cinnamon;  under  parts  creamy  white;  tail  as  in  leucurus.  Full 
summer  pelage  not  seen ;  in  a  worn  specimen  taken  October  3  the  head 
and  fore  back  are  pinkish  cinnamon,  the  rest  of  the  body  in  winter 
pelage. 

Molt. — The  fall  molt  occurs  in  late  September;  a  specimen  taken 
September  26  has  acquired  winter  pelage  over  the  entire  body  except- 
ing the  head ;  others  taken  October  3  still  retain  worn  summer  pelage 
on  the  anterior  half  of  the  body,  the  rest  being  in  full  winter  pelage. 

Measurements. — Average  of  9  adults  from  type  locality :  Total  length,  204 
(19^214)  ;  tail  vertebrae,  62  (54-72)  ;  hind  foot,  39  (3S-40)  ;  ear  from  notch, 
8  (7-9).  Skull:  Average  of  10  adults  (5  males,  5  females)  ;  Greatest  length, 
37.5  (37-39.1)  ;  palatilar  length,  17  (16.5-17.5)  ;  zygomatic  breadth,  21.9  (21.3- 
22.6)  ;  cranial  breadth,  18.5  (18-19)  ;  interorbital  breadth,  9.3  (8.6-9.6)  ;  post- 
orbital  constriction,  13.7  (13.3-14.3)  ;  length  of  nasals,  11.6  (11.2-12.5)  ;  maxil- 
lary tooth  row,  6.7  (6.S-7.4). 


•'••'  Mu.s.  Vert.  Zool. 
■"  Tltnh  State  Agr.  College. 
«  Cleveland  Mus.  Nat.  Hist. 
»^  California  Inst.  Toch. 
•"»  Brigham  Young  Univ. 


174  NORTH  AMERICAN  FAUNA  [No.  56 

Remarks. — Goldman  (1929,  p.  435),  has  described  the  habitat  of 
this  race  as  follows: 

In  the  Grand  Canyon  of  the  Colorado  River,  which  bisects  the  high  plateau 
region  of  northern  Arizona,  antelope  squirrels  are  restricted  mainly  to  the 
broader  terraces  bordering  the  inner  gorge.  These  terraces  are  cut  at  frequent 
intervals  by  side  canyons,  some  of  which  extend  with  sheer  walls  to  the  nearly 
or  quite  precipitous  outer  rim  of  the  main  canyon.  The  higher  parts  of  the 
Coconino  Plateau  along  Grand  Canyon  are  unsuited  to  the  needs  of  antelope 
squirrels  and  the  side  canyons  mentioned,  while  not  absolute  barriers  at  their 
heads,  evidently  tend  to  break  the  continuity  of  range  within  the  main  canyon. 

Specimens  examined. — Total  number,  10,  from  type  locality. 

CITELLUS   LEUCURUS    CINNAMOMEUS    (Merbiam) 

RusTT  Antelope  Squikrel 

Tamias  leucurus  cinnamomeus  Merriam,  North  Amer.  Fauna  3 :  52,  Sept.  11, 

1890. 
Anisonyx  (Animosperniophilus)  leucurus  cinnamomeus  Allen,  Amer.  Mus.  Nat. 

Hist.  Bull.  7:  240,  1895. 
[Spermopliilus  leucurus]  cinnamomeus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser. 

2 :  86,  1901. 
Citellus  leucurus  cinnamomeus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6: 

97,  1905. 
AmmospermopMlus  leucurus  cinnamomeus  Mearns,  U.  S.  Natl.  Mus.  Bull.  56: 

299,  1907. 

Type. — Collected  at  Echo  Cliffs,  Painted  Desert,  Ariz.,  September 
22,  1889,  by  C,  Hart  Merriam  and  Vernon  Bailey;  female  subadult, 
skin  and  skull,  no.  f||-|-,  U.  S.  Natl.  Mus.  (Biological  Survey  collec- 
tion)   (orig.  no.  510). 

Range. — Northeastern  Arizona,  southern  "Utah,  and  southwestern 
Colorado ;  north  to  Mount  Carmel,  Utah  and  Coventry,  Colo. ;  south 
to  Taylor,  Ariz.  (fig.  17).    Zonal  range:  Mainly  Upper  Sonoran. 

External  characters. — Similar  to  G.  I.  leucurtis.,  but  coloration  of 
upper  parts  darker  and  more  reddish  (less  grayish)  ;  hind  legs  darker. 

Cranial  characters. — Skull  similar  to  that  of  leucurus  but  averag- 
ing slightly  larger,  with  longer  nasals. 

Color. — Winter  pelage:  General  tone  of  upper  parts  vinaceous 
cinnamon,  more  or  less  darkened,  especially  on  the  hinder  back  and 
rump  by  mikado  brown,  which  forms  a  subterminal  band  on  most 
of  the  hairs ;  many  of  the  hairs  are  tipped  with  white,  most  strongly 
on  the  fore  back;  sides  of  head  and  neck  washed  with  fuscous;  eye 
ring  buffy  w^hite;  lateral  stripes  creamy  white;  hind  legs  vinaceous 
cinnamon  to  army  brown,  the  feet  buffy  white,  washed  with  pinkish 
cinnamon ;  front  legs  similar,  but  paler ;  tail  above,  mixed  black  and 
white;  tail  beneath,  creamy  white,  bordered  with  black;  under  parts 
white,  washed  with  cartridge  buff.  Summer  pelage:  Upper  parts 
nearly  uniform  vinaceous  cinnamon ;  feet  light  vinaceous  cinnamon ; 
otherwise  as  in  winter. 

Molt. — A  specimen  from  the  Grand  Canyon,  Ariz.,  taken  May  27, 
shows  new  pelage  appearing  on  the  head  and  nape;  one  from  the 
Navajo  Indian  Eeservation,  June  14,  had  nearly  completed  the  spring 
molt,  new  pelage  covering  all  of  the  body  except  the  rump  and 
hind  legs. 

Measurements. — ^Average  of  12  adults  (7  males,  5  females)  from  the  Painted 
Desert  and  Keams  Canyon :  Total  length,  225.8  (215-238)  ;  tail  vertebrae,  73 
(64-79)  ;  hind  foot,  40  (39-43).  STcull:  Average  of  8  adults  (4  males,  4  females) 
from  the  Painted  Desert:  Greatest  length,  89.3   (38.9-39.7);  palatilar  length. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  175 

17.3  (16.5-18)  ;  zygomatic  breadth,  23  (22-23.7)  ;  cranial  breadth,  19.1  (18.5- 
19.7)  ;  interorbital  breadth,  9.5  (9.3-9.8)  ;  postorbital  constriction,  14.1  (13.6- 
14.5)  ;  length  of  nasals,  12.4  (11.9-13)  ;  maxillary  tooth  row,  7.2  (7.1-7.8). 

Remarks. — This  richly  colored  race  has  a  much  more  restricted  dis- 
tribution than  leuGurus,  occurring  chiefly  in  the  deserts  of  north- 
eastern Arizona.  Specimens  from  Fredonia,  in  extreme  northern  Ar- 
izona, do  not  differ  appreciably  from  those  living  on  the  south  side 
of  the  Colorado  River;  at  Kanab  and  Mount  Carmel,  Utah,  however, 
the  animals  are  paler  and  show  evidence  of  intergradation  with 
leucurus.  The  series  from  Bluff  City  and  Noland  Ranch,  on  the 
San  Juan  River,  southeastern  Utah,  is  typical.  One  specimen  from 
Coventry,  Colo.,  seems  referable  to  cinnamorneus,  although  it  appears 
to  represent  an  intrusion  into  the  range  of  C.  I.  pennipes. 

Specimens  examhied. — Total  number,  110,  as  follows : 

Arizona:  Apache  County  (near  Keams  Canyon),  3;  Aztec  Tank  (Coconino 
County),  5;  Cedar  Ranch  Wash  (Locket  Tank,  Coconino  County),  2; 
Deadman  Wash  (Coconino  County),  1;  Fredonia,  4;  Grand  Canyon,  9 
(Indian  Gardens,  6;  Pipe  Creek,  2;  Bass  Camp,  1):  Holbrook  (fs^ivajo 
County),  9;  Jacobs  Pool  (Coconino  County),  4;  Kayenta  (Navajo  Indian 
Reservation),  1;  Keams  Canyon  (Navajo  County),  11;  Lees  Ferry  (north 
side),  3;  Lukachukai  (Navajo  Indian  Reservation),  2;  O'Leary  Peak 
(6,000  feet  altitude),  1;  Oraibi  (Hopi  Indian  Reservation),  4;  Painted 
Desert,  8;  Taylor  (Navajo  County),  1;  Tuba  (Coconino  County),  5; 
Winslow,  12;  Zuni  River  (Apache  County),  1. 

Colorado:  Ashbaugh's  Ranch  (near  McElmo,  Montezuma  County),  1;  Cov- 
entry, 1. 

Utah :  Bluff  City  (San  Juan  River) ,  6 ;  Kanab,  6 ;  Mount  Carmel  (Kane  County) , 
3;  Noland  Ranch  (San  Juan  River),  2;  Notom  (Wayne  County),  2;^" 
Willow  Tank  Spring  (Kane  County),  3.*"" 

CITELLUS  LEUCURUS  PENNIPES  (Howell) 

Colorado  Antbxope  Squierel 

Ammospermophilus  leucurus  pennipes  Howell,  Jour.  Mammal.  12:  162,  May  14, 
1931. 

Type. — Collected  at  Grand  Junction,  Colo.,  November  11,  1895,  by 
A.  H.  Howell;  female  adult,  skin  and  skull,  no.  75683,  U.  S.  Natl. 
Mus.  (Biological  Survey  collection)   (orig.  no.  494). 

Range. — The  Colorado  Valley  and  its  tributaries  (except  the  San 
Juan)  in  western  Colorado,  eastern  Utah,  and  northwestern  New 
Mexico ;  north  to  Vernal,  Utah  and  Rangely,  Colo. :  west  to  Thurber, 
Utah;  south  to  Socorro  Mountains,  N.  Mex.  (fig.  17).  Zonal  range: 
Upper  Sonoran. 

External  characters. — Similar  to  G.  I.  cinno/inomeus^  but  upper 
parts  in  winter  pelage  more  grayish  (less  vinaceous)  and  in  summer 
pelage  darker  and  more  brownish.  Compared  with  C .  I.  leucurus: 
upper  parts  in  whiter  pelage  averaging  more  vinaceous  (less  gray- 
isli)  in  general  tone;  in  summer  pelage  decidedly  more  vinaceous. 

Cranial  characters. — Skull  similar  to  that  of  cinnamorneus  but 
averaging  slightly  larger;  decidedly  larger  than  that  of  leucurus. 

Color. — Winter  pelage  (November)  :  Upper  parts  light  vinaceous 
cinnamon,  the  hairs  on  the  median  dorsal  area  from  crown  to  rump 
extensively  tipped  with  white;  flanks  and  hind  legs  vinaceous  cinna- 

wh  Brlgham  Young  Univ. 


I'^Q  NORTH  AMERICAN  FAUNA  [No.  56 

iiion,  shading  to  pale  pinkish  buff  on  the  hind  feet;  front  feet  sim- 
ilar ;  lateral  stripes  creamy  white ;  tail  above,  mixed  black  and  gray- 
ish white,  shaded  with  the  body  color  at  the  base,  the  hairs  showing 
a  broad  subterminal  band  of  black;  tail  beneath,  creamy  white,  bor- 
dered with  black ;  under  parts  white,  tinged  with  pale  buff.  Summer 
pelage  (June)  :  Upper  parts  light  pinkish  cinnamon,  more  or  less 
darkened  on  the  median  dorsal  area  by  the  fuscous  bases  of  the  hairs 
and  shaded  on  the  shoulders  by  a  wash  of  white;  flanks  and  hind 
legs  light  vinaceous  cinnamon,  shading  to  pinkish  buff  on  the  feet; 
under  parts  buffy  white ;  tail  as  in  the  winter  pelage. 

AIoU. — A  specimen  from  Huntington,  Utah,  taken  in  April,  shows 
the  summer  pelage  coming  in  on  the  head  and  fore  back. 

Measurements. — Average  of  10  adults  (4  males,  6  females)  from  type  locality: 
Total  length,  226.6  (220-239)  ;  tail  vertebrae,  68.8  (60-76)  ;  hind  foot,  39 
(38--41)  ;  ear  from  notch  (dry),  8.7  (7-10).  Skull:  Average  of  9  adults  (5 males, 
4  females)  from  type  locality:  Greatest  length,  40.2  (38.9-41.8);  palatilar 
length,  18.2  (17.8-18.6)  ;  zygomatic  breadth,  23.2  (22.6-24.2)  ;  cranial  breadth, 
18.9  (18.4-19.5)  ;  interorbital  breadth,  9.6  (9.3-10.1)  ;  postorbital  constriction, 
13.7  (13.1-14.5)  ;  length  of  nasals,  12.7  (12-13.7)  ;  maxillary  tooth  row,  7.1 
(6.3-7.5). 

Remarks. — This  race,  apparently  most  closely  related  to  cinna- 
momeus,  differs  from  it  in  being  less  strongly  vinaceous  in  color;  in 
this  respect  it  approaches  leucurus  but  it  has  a  decidedly  larger  skull. 
A  series  in  full  winter  pelage  from  Fruitland  and  Shiprock,  N.  Mex., 
agrees  closely  with  typical  pennipes,  and  differs  markedly  from  the 
series  of  cinnamomeus  from  Bluff  City,  Utah,  lower  down  in  the  same 
valley.  Specimens  from  Jemez,  Rio  Puerco,  and  Socorro  Mountains, 
N.  Mex.,  seem  referable  to  pennipes  and  show  no  approach  to  G.  in- 
terpres.,  which  occurs  on  the  eastern  side  of  the  Rio  Grande  Valley. 

Specimens  examined. — Total  number,  72,  as  follows : 

Colorado:  Fruita,  1;  Grand  Junction,  22;  Hotchkiss,  2;  Rangely  (Rio  Blanco 
County),  1 ;  White  River  (20  miles  east  of  Rangely),  2. 

New  Mexico:  Albuquerque  (35  miles  west),  1;  Fruitland  (San  Juan  County), 
12;  Jemez  (Sandoval  County),  2;  Rio  Puerco  (Valencia  County),  1;  Ship- 
rock  (San  Juan  County),  2;  Socorro  Mountains  (10  miles  northwest),  1. 

Utah:  Emery  County  (near  Huntington),  1;  Henry  Mountains,  2;  Jimction  of 
Green  and  White  Rivers,  1;*^  Lyman  (Wayne  County),  1;  "  Ouray  (8  and 
15  miles  southwest),  11;"  Thurber  (Wayne  County),  4;  Uncompahgre 
Indian  Reservation,  1 ;  *^  Vernal,  4. 

CITELLUS    LEUCURUS    PENINSULAS    (Allen) 
Western  Peninsular  Antelope  SQiniREEii 

Tamias  leucurus  peninsulae  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  5 :  197,  Aug.  IS, 

1893. 
Citellus  leucurus  peninsulae  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3 :  211, 

1903. 
AmmospermopMlus  leucurus  peninsulae  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  299, 

1907. 

Type. — Collected  at  San  Telmo,  Baja  California,  April  30,  1893,  by 
A.  W.  Anthony;  male  adult,  skin  and  skull,  no.  If-Jf,  Amer.  Mus. 
Nat.  Hist.  (orig.  no.  8). 

^  Carnegie  Mus. 

82  Utah  State  Agr.  College. 

88  Field  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  177 

Range. — ^Western  side  of  the  Baja  California  Peninsula;  east  to 
the  base  of  the  San  Pedro  Martir  Mountains ;  south  to  San  Fernando 
(fig.  17).    Zonal  range:  Upper  Sonoran. 

External  characters. — Similar  to  G.  I.  leucurus^  but  darker  through- 
out ;  the  upper  parts  a  deeper  shade  of  vinaceous  and  with  more  black 
intermixed ;  feet  darker  cinnamon ;  tail  more  blackish  above  and  more 
buffy  beneath,  the  hairs  having  two  black  bands. 

Cranial  characters. — Skull  similar  to  that  of  leucurus,  but  averag- 
ing larger. 

Color. — Summer  pelage  (August  22) :  Head  and  upper  parts  pink- 
ish cinnamon,  more  or  less  heavily  mixed  with  black,  the  general  tone 
near  army  brown;  eye  ring  and  lateral  stripes  creamy  white;  front 
legs  and  feet  pinkish  cinnamon  or  mikado  brown;  hind  legs  mikado 
brown  or  vinaceous  cinnamon,  shading  to  light  pinkish  cinnamon  on 
the  feet;  tail  above,  cinnamon  at  base,  the  rest  black,  slightly  tipped 
with  grayish  white;  tail  beneath,  cartridge  buff  or  buffy  white,  bor- 
dered with  black  and  tipped  with  grayish  white ;  under  parts  car- 
tridge buff  or  buffy  white. 

Variation. — One  topotype  (Aug.  21)  has  the  nape  and  shoulders 
rather  heavily  sprinkled  with  grayish  white.  Some  specimens  have 
considerable  black  on  the  terminal  portion  of  the  tail,  due  to  the 
presence  of  the  band  of  black  near  the  base  of  the  hairs.  Winter  (?) 
pelage:  Specimens  taken  August  21  to  23  have  acquired  a  fresh  pe- 
lage covering  the  posterior  half  of  the  body ;  the  general  tone  is  near 
army  brown,  shading  to  vinaceous  cinnamon  on  the  legs  and  to  light 
vinaceous  cinnamon  or  pinkish  buff  on  the  feet. 

Molt. — An  adult  female  taken  August  21  at  San  Telmo  shows  a 
fresh  pelage  covering  the  posterior  half  of  the  back,  similar  in  color  to 
the  summer  pelage.  An  adult  male  from  San  Quintin,  August  8, 
shows  a  fresh  pelage  appearing  on  the  rump ;  an  adult  female  from 
the  same  locality,  August  23,  is  in  similar  condition,  the  new  i)elage 
covering  nearly  the  posterior  half  of  the  body. 

Measurements. — Average  of  5  adults  (2  males,  3  females),  from  type  locality: 
Total  length,  224  (21J>-230)  ;  tail  vertebrae,  74  (72-77)  ;  hind  foot,  39.1  (38.5-40)  ; 
ear  from  notch  (dry),  8  (7-9).  Skull:  Average  of  5  adults  from  type  locality: 
Greatest  length,  39.9  (38.&-41.4)  ;  palatilar  length,  18  (17-19)  ;  zygomatic  breadth, 
23.2  (22.2-23.8)  ;  cranial  breadth,  19  (18.7-19.3)  ;  interorbital  breadth,  9.8  (9.6- 
10)  ;  postorbital  constriction,  14.8  (14-15.2)  ;  length  of  nasals,  12.2  (11.3-12.5)  ; 
maxillary  tooth  row,  7.4  (7-7.7). 

Remarks. — This  subspecies  has  a  rather  limited  range  on  the  west- 
ern side  of  the  Baja  California  Peninsula.  It  is  closely  related  to 
C.  I.  extimus,  which  occupies  the  southern  end  of  the  peninsula,  but 
its  range  is  separated  from  that  of  extimus  by  a  desert  area  occupied 
by  C.  I.  can'jleldae. 

Specimens  examined. — Total  number,  44,  as  follows : 

Baja  California:  Agua  Escondido  (near  Hanson  Laguna),  2;*'  La  Huerta  (west 
base  Hanson  Laguna  Mountains),  1;  Rancho  La  Progresa,  2;"  Rancho 
Viejo  (15  miles  east  of  Alamo),  2;  Rosario,  10;'^*^  San  Fernando,  2;  San 
Quintin,  15;  San  Rafael  Valley  (20  miles  east  of  Ojos  Negros),  1;  San 
Telmo,  8;  Trinidad  Valley,  1." 


**  Amer.  Mus.  Nat.  Hist. 
^  Mus.  Comp.  Zool. 
*«  Los  Angeles  Museum. 
«7  Field  ^fu8.  Nat.  Hist. 

154970—38 12 


I'Jg  NORTH  AMERICAN  FAUNA  [No.  5G 

CITELLUS  LEUCURUS  CANFIELDAE  (Huey) 

MiD-PENINSULAB  AnTELOPE   SQUIEREL 

Ammospermophilus  leucurus  canfieldae  Huey,  San  Diego  Soc.  Nat.  Hist.  Trans.  5 : 
243,  Feb.  27,  1929. 

Type. — Collected  at  Piinta  Prieta,  Baja  California,  Mexico  (lat. 
28°56'  north;  long.  114°12'  west) ,  February  14, 1928,  by  Laurence  M. 
Huey ;  male  adult,  skin  and  skull,  no.  6783,  San  Diego  Soc,  Nat.  Hist. 

Range. — Desert  region  of  central  Baja  California,  from  about  lati- 
tude 30°  southward  over  the  Vizcaino  Desert  to  about  latitude  28° 
(fig,  17),    Zonal  range:  Lower  Sonoran, 

External  characters. — Similar  in  color  to  C.  I.  leucurus  but  darker 
on  body  and  limbs;  under  side  of  tail  with  more  black,  due  to  the 
presence  of  an  additional  black  band  on  some  of  the  hairs.  Compared 
with  G.  I.  peninsulae  and  O.  I.  exthnus^  the  color  is  paler. 

Cranial  characters. — Skull  closely  similar  to  that  of  leucurus.,  but 
with  relatively  wider  interpterygoid  fossa;  smaller  than  that  of 
peninsulae. 

Color. — 'Winter  pelage  (February)  :  Nose  and  front  of  face  cinna- 
mon ;  sides  of  head  grayish  white,  shaded  with  fuscous ;  hairs  on  up- 
per parts,  from  crown  to  rump,  fuscous  subterminally,  tipped  with 
grayish  white  on  fore  back  and  with  light  pinkish  cinnamon  on  middle 
and  hinder  back  (the  general  tone  near  cinnamon  drab) ;  lateral 
stripes  clear  white;  flanks  and  hind  legs,  shoulders,  and  fore  legs, 
vinaceous  cinnamon,  shading  to  light  pinkish  cinnamon  on  the  feet; 
tail  above,  like  the  back  for  about  one-third  of  its  length,  then  mixed 
black  and  grayish  white;  tail  beneath,  creamy  white  in  the  center, 
somewhat  darkened  by  the  presence  of  a  narrow  band  of  black  on 
the  middle  portion  of  some  of  the  hairs;  all  the  hairs  having  a  broad 
subterminal  band  of  black,  tipped  with  white;  mider  parts  creamy 
white.  'Worn  summer  pelage  (September)  :  Upper  parts  and  feet 
nearly  uniform  pinkish  cinnamon  or  light  pinkish  cinnamon.  Young 
(Sept,  9)  :  Similar  to  summer  adults,  but  shoulders  and  fore  back 
heavily  sprinkled  with  white. 

Molt. — A  much  worn  young  individual  taken  September  16  at  Cala- 
mahue  shows  new  pelage  covering  the  head;  an  adult  from  Santa 
Domingo,  September  27,  had  acquired  the  winter  pelage  over  the 
posterior  half  of  the  body. 

Measurements.- — Average  of  5  adults  (2  males,  3  females)  :  Total  length,  220.6 
(215-226)  ;  tail  vertebrae,  70.8  (66-78)  ;  hind  foot,  36  (35-38)  ;  ear  from  notch 
(dry),  8.2  (8-8.5).  Skull:  Average  of  6  adults  (3  males,  3  females)  :  Greatest 
length,  38.5  (37.5-39)  ;  palatilar  length,  17.2  (17-17.5)  ;  zygomatic  breadth,  22.8 
(21.9-22.7)  ;  cranial  breadth,  18.3  (18-19)  ;  interorbital  breadth,  9.3  (8.9-10)  ; 
postorbital  constriction,  13.6  (12.9-14.3)  ;  length  of  nasals,  11.7  (11-12.6)  ;  max- 
illary tooth  row,  6.9  (6.5-7.1). 

RemarTts. — This  race,  occupying  a  desert  area  in  the  middle  of  the 
Baja  California  Peninsula,  is  intermediate  between  leucurus  on  the 
north  and  extimus  on  the  south,  with  both  of  which  it  intergrades 
where  their  ranges  meet. 

Specimens  examined. — Total  number,  15,  as  follows : 

Baja  California:  Calamahue,  4;  Campo  Los  Angeles,  2;^  Jaraguay  (58  miles 
southeast  of  San  Fernando),  2;  Mesquital,  1;*^  Punta  Prieta,  2;^  San  An- 
dres, 1;*°  Santo  Domingo,  2;  Yubay  (30  miles  southeast  of  Calamahue),  1. 


«8  San  Diego  Soc.  Nat.  Hist, 
*^Mus.  Comp.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  179 

CITELLUS  LEUCURUS  EXTIMUS  (Nelson  and  Goldman) 

SoLTHEKN  Peninsular  Antelope  Squirrel 

Ammospermophilus  leucurus  evtimus  Nelson  and  Goldman,  Jour.  Wash.  Acad. 
Sci.  19:  281,  July  19,  1929. 

Type. — Collected  at  Saccaton  (15  miles  north  of  Cape  San  Lucas), 
Baja  California,  Mexico,  December  29,  1905,  by  E.  W.  Nelson  and 
E.  A.  Goldman;  female  adult,  skin  and  skull,  no.  146587,  U.  S.  Natl. 
Mus.  (Biological  Survey  collection)   (orig.  no.  18805). 

Range. — Southern  part  of  the  Baja  California  Peninsula,  from 
Cape  San  Lucas  north  to  about  latitude  28°  (except  the  Vizcaino 
Desert)  ;  ranging  from  sea  level  to  about  1,000  feet  altitude  on  the 
slopes  of  the  mountains  (fig.  17).  Zonal  range:  Lower  Sonoran  and 
Tropical. 

External  characters. — Similar  to  C.  I.  canfleJdae.,  but  larger,  and 
darker  (more  brownish),  especially  on  the  head,  rump,  and  thighs. 
Similar  to  G.  I.  peninsulae  in  color,  but  slightly  paler,  the  rump  and 
thighs  more  vinaceous  in  tone  rather  than  ochraceous. 

Vranial  characters. — Skull  larger  than  that  of  canfieldae  and  0.  I. 
leucurus.,  with  relatively  smaller  bullae;  closely  similar  to  that  of 
peninsulae.,  the  bullae  averaging  slightly  broader  (less  wheel  shaped). 

Color. — Winter  pelage:  Top  of  head  vinaceous  cinnamon,  shaded 
with  fuscous ;  sides  of  head  grayish  white,  shaded  with  fuscous ;  eye 
ring  white;  upper  parts  light  vinaceous  cinnamon,  shaded  with  gray- 
ish white  on  shoulders  and  fore  back  and  heavily  mixed  with  fuscous 
on  middle  and  hinder  back;  lateral  stripes  creamy  white;  hips  and 
thighs  vinaceous  cinnamon;  fore  and  hind  feet  light  vinaceous  cin- 
namon ;  tail  above,  mixed  black  and  buflfy  white ;  tail  beneath,  grayish 
white  or  cartridge  buff,  bordered  with  black  and  tipped  with  buffy 
white;  under  parts  buffy  white.  Summer  pelage  (September)  :  Up- 
per parts  vinaceous  cinnamon,  darkest  on  the  head  and  rump,  be- 
coming light  vinaceous  cinnamon  on  the  shoulders  and  fore  legs. 

Molt. — No  specimens  are  available  to  show  the  progress  of  the 
spring  molt;  the  fall  molt  begins  in  October  on  the  hinder  part  of 
the  body;  a  specimen  from  El  Potrero,  October  31,  has  acquired  new 
pelage  over  the  whole  body  excepting  the  head ;  one  from  Comondu, 
November  7,  is  in  the  same  condition,  the  head  retaining  old  worn 
pelage. 

Measurements. — Average  of  10  adults  from  southern  Baja  California  (Co- 
mondti  to  Cape  San  Lucas)  :  Total  length,  219.8  (208-237)  ;  tail  vertebrae,  79 
(70-87)  ;  hind  foot,  37.2  (3;5-38)  ;  ear  from  notch,  8.9  (8-10).  SJcull:  Average 
of  11  adults  from  Saccaton  and  Cape  San  Lucas :  Greatest  length,  40.3  (39- 
41.6)  ;  palatilar  length,  19  (17.5-20)  ;  zygomatic  breadth,  23  (22.5-23.8)  ;  cranial 
breadth,  18.6  (18.2-19)  ;  interorbital  breadth,  9.9  (9.2-10.3)  ;  postorbital  con- 
striction. 13.5  (12.7-14.9)  ;  length  of  nasals,  12.9  (11.5-13.7)  ;  maxillary  tooth 
row,  7  (6.3-7.6). 

Remarks. — This  race,  occupying  the  southern  end  of  the  peninsula 
of  Baja  California,  is  most  nearly  related  to  peninsulae  of  the  north- 
west coast  region ;  their  ranges  are  separated,  however,  by  the  range 
of  canfieldae,  a  smaller  and  paler  race  occupying  the  desert  region  in 
the  middle  of  the  peninsula. 


IgQ  NORTH  AMERICAN  FAUNA  [No.  56 

SpeciTnens  examined. — Total  number,  70,  as  follows: 

Baja  California:  Aguaje  de  San  Estaban,  1;  Cape  San  Lucas,  24;  Comondii, 
9;  El  Potrero,  2;  La  Paz,  4;  Matancita,  1;  Saccaton  (15  miles  north  of 
Cape  San  Lucas),  4;  San  Bruno,  1;  San  Ignacio,  6;  San  Jose  (30  miles 
north  of  La  Purisima),  2;  San  Jose  del  Cabo,  5;  San  Juanico  Bay,  2;"° 
San  Pablo,  6;  Santana,  3." 

CITELLUS  INTERPRES  (Mebbiam) 

Texas  Antelopb  Sqxjirkel 

TamicCs  interpres  Merriam,  North  Amer.  Fauna  4 :  21,  Oct.  8,  1890. 
SpermopMlus  interpres  Bryant,  Zoe  3 :  208,  October  1892. 
Witellus]  interpres  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  4: 143,  1904. 
Ammospermophilus  interpres  Bailey,  North  Amer.  Fauna  25 :  81,  1905. 
Ammospermophilus  leucurus  interpres  Mearns,  U.  S.  Natl.  Mus.  Bull.  56 :  301, 
1907. 

Type. — Collected  at  El  Paso,  Tex.,  December  10,  1889,  by  Vernon 
Bailey;  female  adult,  skin  and  skull,  no.  |f^^,  U.  S.  Natl.  Mus. 
(Biological  Survey  collection)  (orig.  no.  762). 

Range. — ^Western  Texas  and  south-central  New  Mexico,  north  to 
the  Manzano  Mountains;  east  to  the  Pecos  Eiver  Valley  and  the 
Castle  Mountains,  Tex.;  west  to  the  eastern  side  of  the  Rio  Grande 
Valley  in  New  Mexico;  south  to  Jaral,  Coahuila  (fig.  17).  Zoned 
range:  Lower  Sonoran. 

^External  characters. — Closely  similar  in  winter  pelage  to  G .  leucurus 
leucurus.^  but  differing  from  it  in  having  an  additional  black  band 
on  the  tail  hairs ;  coloration  much  paler  and  more  grayish  (less  red- 
dish) than  in  G.  I.  cinnamomeus. 

Granial  characters. — Skull  similar  to  that  of  cinnamomeus  but 
with  superior  outline  flatter  and  brain  case  shallower ;  nasals  broader 
at  posterior  end,  truncated  squarely  on  a  line  with  the  ends  of  the 
premaxillae ;  upper  tooth  row  shorter. 

Golor. — Winter  pelage:  Upper  parts  light  drab  or  drab  gray  (the 
tips  of  the  hairs  white,  with  a  subterminal  band  of  fuscous) ;  nose 
and  front  of  face  washed  with  pinkish  cinnamon;  eye  ring  white; 
front  and  hind  legs,  and  hips,  pinkish  cinnamon  or  light  pinkish  cin- 
namon; feet  light  pinkish  cinnamon,  shaded  with  buffy  white  5  tail 
above,  mixed  black  and  white,  with  a  patch  of  light  pinkish  cinna- 
mon at  the  proximal  end ;  tail  beneath,  creamy  white,  bordered  with 
black  and  with  a  free  black  band  on  the  middle  portion  of  some  of 
the  hairs ;  under  parts  white. 

Variation. — Two  specimens  from  the  Manzano  Mountains,  N.  Mex., 
are  slightly  darker  (pale  fawn  color)  on  the  rump  and  hind  legs. 

Molt. — A  specimen  taken  at  Boquillas,  Tex.,  May  23,  is  in  a  badly 
worn  pelage,  and  shows  new  hair  coming  in  on  the  head  and  fore 
back. 

Measurements. — Average  of  10  adults  (8  males,  2  females)  from  El  Paso, 
Tex. :  Total  length,  226  (220-235)  ;  tail  vertebrae,  74.2  (68-84)  ;  hind  foot,  37.8 
(36-40);  ear  from  notch  (dry),  9.8  (8-11).  Skull:  Average  of  14  adults  (8 
males,  6  females)  from  El  Paso:  Greatest  length,  39.3  (37.7-^0.5);  palatilar 
length,  17.3  (16-18.2)  ;  zygomatic  breadth,  22.7  (21.5-23.8)  ;  cranial  breadth, 
18.9  (lS-19.6)  ;  interorbital  breadth,  9.9  (9.4-10.5)  ;  postorbital  constriction,  14.5 
(13.8-15.3)  ;  length  of  nasals,  12.6  (11.8-13.8)  ;  maxillary  tooth  row,  6.6  (6.4^6.9), 


»oAmer.  Mus.  Nat.  Hist. 
^  Mus.  Comp.  Zool. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  Igl 

Remarks. — The  range  of  this  species  seems  to  be  restricted  to  the 
region  east  and  north  of  the  Rio  Grande.  There  is  no  evidence  of 
intergradation  with  cinnamomeus ;  the  latter  is  known  from  speci- 
mens taken  in  the  Socorro  Mountains,  a  few  miles  west  of  the  Rio 
Grande,  whereas  inferpres  is  known  from  the  eastern  side  of  the  river, 
at  a  point  nearly  opposite. 

/Specimens  examined. — Total  number,  62,  as  follows : 

Coahuila:  Jaral,  l.°^ 

New  Mexico:  Manzano  Mountains   (east  foothills),  2;  Organ  Mountains,  1;*' 

San  Andres  Mountains,  11 ;  Socorro  (10  miles  northeast),  1. 
Texas:  Boquillas,  3;  Castle  Mountains  (Crockett  County),  1;  El  Paso,  32;  Fort 

Lancaster   (near  Sheffield,  Crockett  County),  1;   Franklin  Mountains   (10 

miles  north  of  El  Paso),  6;  Guadalupe  Mountains   (south  end),  1;  High 

Bridge,  Pecos  River  (mouth),  1;  Sierra  Blanca,  1. 

CITELLUS   INSULARIS    (Nelson  and  Goldman) 
EspiKiTU  Santo  Antelope  Squirrel 

Ammospermophilus  leucuriis  insularis  Nelson  and  Goldman,  Biol.  Soc.  Wash. 

Proc.  22 :  24,  Mar.  10,  1909. 
Citellus   leucurus  insularis  Elliot,   Sup.   Check-list  Mammals  North   Amer.,   p. 

28,  1917. 

Type. — Collected  on  Espiritu  Santo  Island,  Gulf  of  California, 
Baja  California,  Mexico,  February  7,  1906,  by  E.  W.  Nelson  and 
E.  A.  Goldman ;  female  adult,  skin  and  skull,  no.  146783,  U.  S.  Natl. 
Mus.  (Biological  Survey  collection)  (orig.  no.  19072). 

Range. — Espiritu  Santo  Island,  Baja  California  (fig.  17).  Zonal 
range:  Tropical. 

External  characters. — Closely  similar  to  C.  leucurus  extimus  in 
color,  but  larger,  and  slightly  darker  on  flanks  and  hind  legs;  tail 
about  same  length. 

Cranial  characters. — Skull  similar  to  that  of  extimus  but  larger 
in  all  dimensions  except  the  maxillary  tooth  row,  in  which  the  ante- 
rior premolar  {pm^)  is  lacking  entirely  in  about  half  the  specimens 
and  very  rudimentary  in  the  rest. 

Color. — In  worn  winter  pelage  practically  as  in  extimus.,  except 
on  the  flanks  and  hind  legs,  which  are  light  pinkish  cinnamon.  The 
fresh  pelage  is  not  represented  in  the  series  examined. 

Measurements. — Average  of  7  adults  from  type  locality :  Total  length,  229 
(210-240)  ;  tail  vertebrae,  78  (71-83)  ;  hind  foot,  38.3  (36-40)  ;  ear  from  notch, 
9.1  (8-11).  Skull:  Average  of  5  adults  from  type  locality:  Greatest  length,  41.8 
(40.3^^2.4)  ;  palatilar  length,  18.4  (18-19)  ;  zygomatic  breadth,  24.2  (23.9-24.7)  ; 
cranial  breadth,  18.9  (18.7-19)  ;  interorbital  breadth,  10.1  (9.8-10.6)  ;  postorbital 
constriction,  13.8  (13.4-14)  ;  length  of  nasals,  13.6  (12.3-14.3)  ;  maxillary  tooth 
row,  6.5  (6.4-6.7). 

Remarks. — Although  resembling  the  mainland  race  (extimus)  very 
closely  in  color  this  island  species  has  developed  pronounced  cranial 
and  size  characters. 

Specimens  examined. — Total  number,  14,  from  type  locality. 

»2  Field  Mus.  Nat.  Hist. 
»» State  College,  N.  Mex. 


]^32  NORTH  AMERICAN  FAUNA  [No.  56 

GITELLUS  NBLSONI    (Mereiam) 

San  Joaquin  Antelope  Squirrel 

Spermophilus  nelsoni  Merriam,  Biol.  Soc.  Wash.  Proc.  8 :  129,  Dec.  28,  1893. 
Citellus  nelsoni  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3 :  290,  1904. 
Ammospermophilus  nelsoni  Lyon  and  Osgood,  U.  S.  Natl.  Mus.  Bull.  62 :  172,  1909. 
AmmospermopMlus  nelsoni  a,mplus  Taylor,  Calif.  Univ.  Pubs'.,  Zool.  17 :  15,  1916 
(20  miles  south  of  Los  Banos,  Merced  County,  Calif.). 

r?/^e.— Collected  at  Tipton,  Tulare  County,  Calif.,  June  24,  1893, 
by  C.  P.  Streator  •  male  adult,  skin  and  skull,  no.  54651,  U.  S.  Natl. 
Mus.  (Biological  ourvey  collection)  (orig.  no.  2968). 

Range. — San  Joaquin  Valley,  Calif.,  from  Los  Banos  south  to  Fort 
Tejon;  west  to  the  Carriso  Plain  and  Cuyama  Valley  (fig.  17). 
Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  G.  leucurus  leucurus  but  colors 
more  buffy  (less  grayish)  in  both  winter  and  summer  pelage. 

Cranial  characters. — Skull  similar  to  those  of  leucurus  and  G.  I. 
cinnamomeus.^  but  larger,  with  heavier  and  more  wide  spreading  zy- 
gomata and  larger  audital  bullae, 

Golor. — Summer  pelage;  Upper  parts  uniform  pinkish  buff  or  pale 
pinkish  buff;  a  narrow  stripe  of  creamy  white  on  either  side  of  the 
dorsal  area,  from  the  shoulders  to  the  rump ;  fore  and  hind  limbs  light 
pinkish  cinnamon,  the  feet  pinkish  buff;  tail  like  the  back  for  the 
basal  third  above^  the  remainder  black  or  fuscous  black,  edged  with 
creamy  white;  tail  beneath,  creamy  w^hite,  with  a  subterminal  band 
of  blackish;  under  parts  creamy  white.  Winter  felage  (October)  : 
General  tone  of  upper  parts  varying  from  wood  brown  to  light  drab, 
the  hairs  with  a  subterminal  band  of  fuscous  and  tipped  with  pinkish 
buff  or  buffy  white ;  front  legs  light  pinkish  cinnamon  next  the  body, 
shading  to  pinkish  buff  on  the  feet ;  hind  legs  and  thighs  pinkish  cin- 
namon or  sayal  brown. 

Molt. — The  spring  molt  occurs  in  late  April  or  early  May.  Speci- 
mens taken  April  15  are  still  in  worn  winter  pelage;  a  female  from 
Carriso  Plain,  April  27,  has  nearly  completed  the  molt,  there  being 
a  patch  of  winter  pelage  still  remaining  on  the  head  and  another  patch 
on  the  hinder  back;  another  female  taken  at  Bakersfield,  May  6, 
shows  new  pelage  coming  in  irregularly  on  the  head,  sides,  and  middle 
of  the  back.  The  fall  molt  occurs  in  September  and  progresses  from 
the  rump  forward ;  a  specimen  taken  at  Mendota,  September  28,  had 
acquired  fresh  winter  pelage  over  the  posterior  half  of  the  back 
and  sides;  another  taken  at  Alila,  October  8,  has  the  fresh  pelage 
covering  all  but  the  head  and  face. 

Measurements. — Average  of  10  adult  males  from  type  locality :  Total  length, 
231.2  (218-240)  ;  tail  vertebrae,  70  (68-79)  ;  hind  foot,  41.2  (40-43)  ;  ear  from 
notch  (dry),  8.2  (8-9).  Average  of  10  adult  females  from  type  locality:  Total 
length,  229.9  (221-237)  ;  tail  vertebrae,  67.4  (62^72)  ;  hind  foot,  39.7  (39^1)  ; 
ear  from  notch,  8.5  (8-9.5).  Skull:  Average  of  12  adults  (3  males,  9  females) 
from  type  locality:  Greatest  length,  41.1  (40-41.9)  ;  palatilar  length,  18.9 
(18-19)  ;  zygomatic  breadth,  24.5  (23.5-25.7)  ;  cranial  breadth,  19.6  (18.8-20.6)  ; 
interorbital  breadth,  10.1  (9.6-10.5)  ;  postorbital  constriction,  13.8  (13.5-14.3)  ; 
length  of  nasals,  12.4  (11.2-13)  ;  maxillary  tooth  row,  7.7  (7.2^8.5). 

Remarks. — This  species  is  quite  distinct  from  leucurus.^  and  the 
ranges  of  the  two  do  not  overlap,  so  far  as  known.  Its  habits  are 
bimilar  to  those  of  the  other  members  of  the  subgenus  Ammospermo- 
philus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  183 

Comparison  of  a  typical  series  of  '■'■amplus''''  with  typical  nelsoni 
shows  the  differences  to  be  too  slight  to  warrant  recognition  in  nomen- 
clature. The  skulls  average  slightly  larger — about  one  millimeter  in 
iength  and  in  zygomatic  breadth.  No  appreciable  difference  in  color 
can  be  detected. 

Specimens  examined. — Total  number,  210,  as  follows : 

California:  Adobe  Station  (near  Keru  Lake),  1;  Alcalde  (Fresno  County),  7; 
Alila  (=  Earlimart),  8;  Bakersfield  (8  miles  northeast  and  20  miles  south), 
37 ;  "  Buena  Vista  Lake,  3  ;  Carriso  Plain,  11 ;  Coalinga,  3 ;  Cuyama  Valley,  10 ; 
Dos  Falos,  2;  Firebaugh  (Fresno  County),  1 ;  **  Five  Willow  Springs  (23 
miles  southeast  of  Simmler),  4;  Huron  (Fresno  County),  8;  Los  Banos, 
30;*"  Lerdo  (Kern  County),  2;  Maricopa,  4;  "'  McKittrick,  5;  Mendota 
(Fresno  County),  7;  Panoche  Creek  (10^15  miles  southwest  of  Mendota), 
2;°°  Panoche  Pass  (Fresno  County),  1;"'  Poso  (=Famoso,  Kern  County), 
3;  Rose  Station  (4  miles  north  of  Fort  Tejon),  5;  ^  Santa  Maria  Springs  (7 
miles  southwest  of  McKittrick),  1 :  Simmler  (8  miles  east,  on  Carriso  Plain), 
11;  Stanley  (=Turk,  Fresno  County),  1;  Sunset  (=  Hazelton,  Kern 
County),  5;  Temploa  Mountains,  2;  Tipton  (Tulare  County),  36. 

Subgenus  XEROSPERMOPHILUS  Merriam 

[Characters  on  p.  45] 

Key  to  Species  and  Subspecies 

a\  Under  side  of  tail  white mohavensis  (p.  1S3) 

a'.  Under  side  of  tail  not  white. 
&\  Upper  parts  drab. 

c\  Darker tereUcaudus{^.  185) 

y.  Paler  (light  drab) clilorus  (p.  188) 

b".  Upper  parts  vinaceous  cinnamon  or  cinnamon  drab. 

c\  Paler  (light  vinaceous  cinnamon) tercticaudus  (p.  185) 

c\  Darker  (vinaceous  cinnamon  or  cinnamon  drab). 

d\  Habitat  Arizona  and  Sonora neglectus  (p.  187) 

d^.  Habitat  Baja  California uijricus  (p-  190) 

CITELLUS  MOHAVENSIS   (Merriam) 

Mohave  Ground  Squirrel 

Spermopkiliis  moluivcnsis  Merriam,  North  Amer.  Fauna  2:15,  Oct.  30,  1889, 
[Citcllus]mohuvvnsis  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  19U4. 
[Citellus]  tercticaudus  mohavensis  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3: 
291,  1904. 

Type. — Collected  near  Rabbit  Springs,  about  15  miles  east  of  Hes- 
peria,  San  Bernardino  County,  Calif.,  June  29,  1886,  by  Frank  Ste- 
phens (Grinnell  and  Dixon,  1918,  p.  667) ;  male  adult,  skin  and  skull, 
no.  186469,  U.  S.  Natl.  J\lus.  (no.  -ffH,  Merriam  collection)  (orig. 
no.  315). 

Range. — Mohave  Desert,  Calif.,  west  to  Palmdale,  Los  Angeles 
County;  north  to  Haiwee  Meadows,  Inyo  County,  south  to  Rabbit 
Springs,  San  Bernardino  County  (fig.  18).  Zonal  range:  Lower 
Sonoran. 

External  characters. — Similar  in  external  appearance  to  C.  town- 
sendii  mollis  but  general  tone  of  upper  parts  more  pinkish  (less  gray- 
ish) without  trace  of  mottling;  imder  side  of  tail  clear  whitish  instead 
of  cinnamon. 


»<]Mus.  Vert.  /ool. 

^^  W.  T.  Shaw  collection. 

»8  Field  Mus.  Nat.  Hist. 


184 


NORTH  AMERICAN  FAUNA 


[No.  56 


Cranial  characters. — Skull  similar  to  that  of  C.  tereticaudus  but 
averaging  larger;  slightly  larger  than  that  of  O.  townsendii  mollis 
and  differing  from  it  in  the  characters  distinguishing  the  subgenus 
Xerospermophilus ;  brain  case  short  and  broad;  rostrum  short,  the 
nasals  ending  nearly  on  a  line  with  the  premaxillae ;  zygomata  heavy, 
widely  expanded,  and  twisted  so  that  they  occupy  a  position  about 

midway  between  ver- 
tical and  horizontal; 
postorbital  processes 
broad  at  base,  nar- 
rowing rapidly  to 
slender  tip,  which  is 
depressed ;  incisors 
moderately  short  and 
stout,  slightly  re- 
curved; audital  bul- 
lae broad  and  evenly 
rounded,  consider- 
ably inflated. 

Color.  —  Unworn 
•winter  pelage 
(March)  :  Upper 
parts  uniform  light 
drab,  with  a  tinge  of 
light  vinaceous  cin- 
namon, strongest  on 
the  forehead ;  front 
feet  light  pinkish 
cinnamon;  hind  feet 
pale  buff,  washed 
with  light  pinkish 
cinnamon  or  pinkish 
buff;  tail  above  fus- 
cous, overlaid  with  creamy  white;  tail  beneath,  clear  creamy  white; 
under  parts  creamy  white.  Summer  pelage  (May)  :  Upper  parts 
drab  or  avellaneous. 

Molt. — A  female  specimen  taken  May  12  shows  a  new  pelage  cover- 
ing the  head,  shoulders,  and  most  of  the  back. 

Measurements. — ^Average  of  11  adults  from  Mohave  Desert,  Salt  Wells  Valley, 
and  Palmdale:  Total  length,  222.5  (210-230)  ;  tail  vertebrae,  65.5  (57-72)  ;  hind 
foot,  35.5  (32^38).  Skull:  Average  of  11  adults  from  Mohave  Desert,  Salt  Wells 
Valley,  and  Little  Lake:  Greatest  length,  38.7  (38.1-40)  ;  zygomatic  breadth, 
24.3  (23.5-25.3)  ;  breadth  of  cranium,  18.2  (17.6-19.3)  ;  interorbital  breadth, 
8.7  (7.1-9.6);  postorbital  constriction,  12.7  (11.8-13.3);  length  of  nasals,  12.9 
(12.2-13.5)  ;  maxillary  tooth  row,  7.8  (7.6-8). 

Remarks. — The  Mohave  ground  squirrel  is  remarkable  for  the  lim- 
ited extent  of  its  range  and  for  the  fact  that  it  has  no  near  relatives. 
It  is  readily  distinguished  from  the  other  unspotted  ground  squirrels 
by  the  white  under  surface  of  the  tail.  Its  range  apparently  meets 
but  does  not  overlap  that  of  tereticaudus.  The  latter  occupies  the 
eastern  side  of  the  Mohave  Desert  as  far  west  as  Daggett  (Elliot's 
record  of  C.  mohavensis  at  Daggett  (1904,  p.  291)  is  an  error,  all  the 
specimens  taken  there  being  C.  fereticaudics) ,  while  mohavensis  occurs 
on  the  western  side,  along  the  Mohave  River. 


Figure  18. — Distribution  of  Citellus  mohaven»is. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  185 

Specimens  examined. — Total  number,  23,  as  follows: 

California:  Haiwee  Meadow  (10  miles  south  of  Owens  Lake),  1;  Hesperia  (San 
Bernardino  County),  1;"'  Little  Lake  (Inyo  County),  2;**  Mohave,  1; 
Mohave  Desert,  2;  "Mohave  River"  (=Rabbit  Springs,  15  miles  east  of 
Hesperia),  6;  Oro  Grande  (San  Bernardino  County),  1;  Palmdale,  1;  Salt 
Wells  Valley  (=north  end  Mohave  Desert),  7;  Victorville,  1." 

CITELLUS  TERETICAUDUS   (Baied) 
[Synonymy  under  subspedes] 

Speciftc  characters. — Similar  in  general  external  appearance  to  C. 
toiunsendii  mollis,  but  never  with  any  traces  of  dappling ;  tail  longer 
and  less  bushy ;  ears  a  mere  rim ;  hind  foot,  32-40  mm ;  tail,  60-102 ; 
skull  length,  34.3-39.3.  Skull  closely  similar  to  that  of  C.  mohavensis. 
Upper  parts  vinaceous  cinnamon,  pinkish  cinnamon,  light  drab,  cin- 
namon drab,  or  ecru  drab;  tail  beneath,  drab  or  buff  (never  white). 

CITELLUS  TERETICAUDUS  TERETICAUDUS  (Baird) 

ROTJND-TAILED  GEOUND  SQITIBREL 

(Pis.  27,  C;  32,  C) 

Spermophilus  tereticaudiis  Baird,  Pacific  R.  R.  Rept.  8:315,  1857. 

Citellus  tereticaudus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3 :  211,  1903. 

Citellus  eremonomus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3:  243,  1903. 

(Furnace  Creek,  Death  Valley,  Calif.) 
Citellus  tereticaudus  mohavensis  Elliot,  Ibid,  p.  291,  1904    (not  Spermophilus 

mohavensis  Merriam). 
Citellus  tereticaudus  vociferans  Huey,  Biol.  Soc.  Wash.  Proc.  39:  29,  1926  (San 

Felipe,  Baja  California). 

Ootypes. — Collected  at  Old  Fort  Yuma,  Imperial  County,  Calif., 
by  Maj.  G.  H.  Thomas;  male  subadult,  skin  and  skull,  no.  Hit; 
female  immature,  in  alcohol,  no.  2490,  U.  S.  Natl.  Mus. 

Range. — Deserts  of  southern  California  and  northeastern  Baja 
California;  north  to  Death  Valley,  Calif.,  and  Ash  Meadows,  Nev.; 
east  to  Bunkerville,  Nev.,  and  extreme  northwestern  Arizona;  south 
to  San  Felipe  Bay,  Baja  California;  west  to  Kramer  on  the  Mohave 
Desert  (Grinnell  and  Dixon,  1918,  p.  669)  and  to  La  Puerta,  San 
Diego  County,  on  the  Colorado  Desert  (fig.  19).  Zonal  range:  Lower 
Sonoran. 

External  characters. — Similar  to  C.  toirnsendii  mollis  but  tail  much 
longer;  coloration  more  pinkish  (less  grayish);  under  parts  white 
instead  of  buff.  Compared  with  C.  tnohavensis :  Tail  longer,  less 
bushy,  and  nearly  unicolor  (not  white  beneath). 

Cranial  characters. — Skull  similar  to  that  of  mohavensis^  but  aver- 
aging slightly  smaller. 

Color. — Cinnamon  phase  (unworn  winter  pelage)  :  Upper  parts 
light  vinaceous  cinnamon,  the  hairs  with  narrow  whitish  bands;  sides 
of  nose  and  face  washed  with  dull  white  or  pale  smoke  gray ;  eye  ring 
whitish;  feet  white  or  cartridge  buff;  basal  half  of  tail  above^  like 
back;  terminal  half  shaded  with  fuscous  and  edged  with  whitish; 
tail  beneath,  cartridge  buff;  under  parts  white.  Drah  phase:  Upper 
parts  drab,  some  individuals  shaded  witli  cinnamon.  In  summer  the 
pelage  is  thinner  and  slightly  paler. 

"'  lios  Angeles  Museum. 
••Mus.  Vert.  Zool. 
"E.  T.  Seton  collection. 


186 


NORTH  AMERICAN  FAUNA 


[No.  56 


Molt. — The  spring  molt  occurs  from  the  middle  of  March  to  the 
middle  of  May,  varying  with  the  locality.  There  is  no  clear  evidence 
of  a  fall  molt,  but  judging  from  the  full,  silky  pelage  of  winter 
specimens,  it  seems  probable  that  there  is  a  renewal  of  the  pelage  in 

Measurements.- — Average  of  11  adults  from  Fort  Yuma  and-  Pilot  Knob,  Calif. : 
Total  length,  249.5  (235-266)  ;  tail  vertebrae,  91.1  (81-102)  ;  hind  foot,  36.2 
(33-38).  Skull:  Average  of  16  adults  from  same  region:  Greatest  length,  36.5 
(34.9-38.3)  ;  palatilar  length,  16.9  (16-18.3)  ;  zygomatic  breadth,  23  (21.8-24)  ; 
breadth  of  cranium,  17.5  (16.8-18.5)  ;  interorbital  breadth,  8.9  (8.2-10.3)  ; 
postorbital  constriction,  12.4  (11.7-13.1)  ;  length  of  nasals,  11.7  (10.3^12.8) ; 
maxillary  tooth  row,  7.2  (6.7-7.8). 

Remarks. — The  round-tailed  ground  squirrel  has  a  wide  range  on 
the  deserts  of  California  and  Baja  California,  and  a  closely  related 
form  {C.  t.  neglectus)  occupies  a  large  part  of  western  Arizona  and 

northern  S  o  n  o  r  a. 
Although  closeljT-  re- 
lated to  G.  mohaven- 
sis  it  is  quite  distinct 
from  that  species  and 
apparently  their 
ranges  do  not  over- 
lap/ Its  r  e  s  e  m- 
blance  in  color  to 
mollis  does  not  of 
course  indicate  close 
relationship. 

'"''Gitellus  er&mono- 
'mus^''  of  Elliot  was 
based  on  a  small 
series  from  Death 
Valley  ta,ken  in  late 
April.  There  is  now 
available  from  this 
valley  a  series  of 
over  30  specimens, 
representing  all  the 
pelage  variations, 
and  showing  that 
there  are  two  color 
phases  with  numer- 
o  u  s  intermediate 
specimens.  The  cin- 
namon phase  is  rep- 
resented in  both  summer  and  winter  pelage  and  shows  no  appreciable 
differences  from  typical  tereticaudus  from  the  Colorado  Valley. 
The  drab  phase  is  likewise  represented  in  both  pelages.  A  consider- 
able series  from  Daggett,  Calif.,  contains  specimens  representative 
of  both  color  phases  and  some  intermediates. 

Comparison  of  a  series  of  30  topotypes  of  '■''CiteTlus  vociferans'^'' 
Huey  with  large  series  of  typical  tereticaudus  shows  that  the  alleged 

1  Elliot's  assignment  (1904,  p.  291)  of  mohavensis  as  a  subspecies  of  tereticaudus  is 
based  on  a  misidentification  of  specimens  from  Daggett,  Calif.,  these  being  typical 
tereticaudus. 


Figure  19. — Distribution  of  the  subspecies  of  Citellus  tere- 
ticaudus: 1,  G.  t.  tereticaudus ;  2,  C.  t.  chlorus;  3,  C.  t. 
neglectus;  4,  C.  t.  apricus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  187 

characters  of  '"'■'vociferans'''  are  covered  by  individual  and  seasonal 
variation  in  tereticmidus. 
Specimens  examined. — Total  number,  231,  as  follows: 

Baja  California:  Gardner's  Laguna,  Salton  River,  1;  Mexicali,  4;*  San  Felipe, 

24 ;  - "  San  Felipe  Bay,  12. 

California:  Amargosa  Valley,  1;  Bard  (Imperial  County),  17;  ="  Baregas 
Springs  (=Borego,  San  Diego  County),  1;  Barstow,  2;*°  Blythe  Junction 
(Riverside  County),  4;^  Brawley,  1;  Calexico,  1;  Colorado  Desert  (Carrizo 
Creek  and  Salt  Creek),  5;  Colorado  River  (opposite  Parker,  Ariz),  1; 
Coyote  Well  (Imperial  County),  4;*  Daggett,  34; '«  Death  Valley,  51;'*" 
Fort  Yuma,  6;  Indian  Well,  New  River  (San  Diego  County),  1;  Ivanpah 
(San  Bernardino  County),  1 ;  Laguna  Dam  (Imperial  County),  4 ;  La  Puerta 
(San  Diego  County),  4 ;  ^ * ^  Needles,  29;  Pilot  Knob  (Imperial  County),  6;' 
Riverside  County  (25  miles  southwest  of  Ehrenburg,  Ariz.),  1;  Salton 
Lake,  6.* 

Nevada:  Ash  Meadows  (Nye  County),  4;  Bunkerville  (Clark  County),  1;  Las 
Vegas,  1;"  Muddy  River  (Clark  County),  2;'  Pahrump  Valley,  1;  St. 
Thomas,  1.' 

CITELLUS  TERETICAUDUS  NEGLECTUS    (Mereiam) 

Arizona  Round-tailed  Ground  Squibkel 

SpermophiJus  neglcctus  Merriam,  North  Amer.  Fauna  2 :  17,  Oct.  30,  1889. 
Spermophilus  sonorietisis  Ward,  Amer.  Nat.  25 :  158,  1891  (Hermosillo,  Sonora, 

Mexico ) . 
Anisonyx  (Ictidomys)  tereticaudus  Allen,  Amer.  Mus.  Nat.  Hist.  Bull.  7:  238, 

1895. 
[Citellus]  negJectus  Trouessart,  Cat.  Mamm.,  Sup.,  p.  341,  1904. 
Citelliis  tereticandtis  arizonae  Grinnell,  Biol.   Soc.  Wash.  Proc,  31 :   105,  1918 

(Tempe,  Ariz.). 

Type. — Collected  at  Dolan  Spring,  12  miles  northwest  .of  Chloride, 
Mohave  County,  Ariz.,  Februarv  9,  1889,  by  Vernon  Bailey;  male 
adult,  skin  and  skull,  no.  186470,  U.  S.  Natl.  Mus.  (no.  ||^,  Merriam 
collection)  (orig.  no.  566). 

Range. — Western  Arizona  and  western  Sonora;  north  to  Detrital 
Valley,  Mohave  County,  Ariz.;  east  to  Mountain  Spring,  Pima 
County;  south  to  Camoa,  Sonora;  west  to  the  Colorado  River  and 
Gulf  of  California  (fig.  19).    Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  C.  t.  tereticaudus  but  darker, 
with  shorter  tail  and  hind  foot. 

Cranial  characters. — Skull  similar  to  that  of  tereticaudus  but  aver- 
aging slightly  larger,  with  narrower  rostrum  and  interorbital  region ; 
nasals  longer. 

Color. — Winter  pelage  (February)  :  Upper  parts  cinnamon  drab 
or  vinaceous  cinnamon,  the  hairs  with  short  whitish  tips;  tail  above, 
same  color  as  back,  tipped  with  fuscous  and  edged  with  buffy  white; 
otherwise  as  in  tereticaudus.  Summer  'pelage:  Similar  to  the  winter 
pelage,  but  shorter,  harsher,  and  averagmg  more  pinkish. 

Molt. — ^A  specimen  (  $  adult)  from  Fort  Mohave,  Ariz.,  March  11, 
is  in  a  much  worn  pelage,  with  new  hair  covering  the  head;  an  adult 
male  from  Gadsden,  Ariz,,  April  10,  shows  about  the  same  condi- 
tion; an  adult  female  from  Texas  Hill,  Ariz.,  April  24,  has  acquired 
a  new  pelage  over  most  of  the  body,  excepting  the  rump;  several 

"  San  Diego  Soc.  Nat.  Hist. 
'  D.  R.  Diclcey  collection. 
*  MuR.  Vert.  Zool. 
■•  Univ.  Michigan  Mus.  Zool. 
"Field  Mus.  Nat.  Hist. 
''California  Inst.  Tech. 


2gg  NORTH  AMERICAN  FAUNA  [No.  56 

specimens  from  Ortiz,  Sonora,  taken  May  12,  are  in  badly  worn 
pelage,  with  new  hair  appearing  on  the  head. 

Measurements. — Average  of  10  adults  (7  males,  3  females)  from  Dolan 
Spring,  Mellen,  and  Fort  Mohave,  Ariz.:  Total  length,  227  (204-247);  tail 
vertebrae.  72  (60-84);  hind  foot,  34.4  (32-37).  Average  of  5  adult  males 
from  Parker,  Ariz.:  Total  length,  233  (225-243)  ;  tail  vertebrae,  85.8  (77-95)  ; 
hind  foot,  35.5  (34.5-37).  Skull:  Average  of  10  adults  (6  males,  4  females) 
from  Dolan  Spring,  Fort  Mohave,  and  Mellen.  Ariz. :  Greatest  length,  37.1 
(35.3-39.3)  ;  zygomatic  breadth,  23.2  (22.2-23.8)  ;  breadth  of  cranium,  17.9 
(17.3-18.3)  ;  interorbital  breadth,  8.3  (7.8-9)  ;  postorbital  constriction,  12.3 
(12-12.7)  ;  length  of  nasals,  12.6  (11.8-13.7)  ;  maxillary  tooth  row,  7.6  (7.3-8). 

Weight. — Two  specimens,  taken  by  Vernon  Bailey,  near  Tucson,  weighed, 
respectively,  116  and  133  g. 

Remarks. — This  ground  squirrel,  originally  described  as  a  distinct 
species,  now  proves  to  be  a  closely  related  race  of  tereticaudus.  It 
has  been  redescribed  twice,  under  the  names  Spennophilus  sonoriensis 
and  Citellus  tereticaudus  '•''arizonae''\  both  Ward  and  Grinnell  ap- 
parently having  overlooked  Merriam's  description  of  neglectus  in 
their  comparisons.  Large  series  of  specimens  from  the  type  locality 
of  '•'' sonoriensis^''  and  from  various  points  in  central  Arizona  show  no 
important  differences  from  typical  neglectus  from  northwestern  Ari- 
zona. The  Sonoran  series  apparently  has  slightly  shorter  nasals 
(average,  11.6  mm)  but  in  the  absence  of  any  color  characters,  it 
seems  best  not  to  recognize  this  form  by  name. 

Specimens  examined. — Total  number,  292,  as  follows : 

Arizona:  Adonde  (Yuma  County),  4;  Ajo  1;  Cibola  (Yuma  County),  2;* 
Colorado  River,  at  Monument  no.  204,  10;  Colorado  River,  5  miles  north- 
east of  Laguna,  3;°  Congress  Junction,  4;  Continental  (Pima  County),  1; 
Coyote  Mountains  (Pima  County),  1;  Dolan  Spring  (Mohave  County),  3; 
Dome  (Yuma  County),  2;  Fort  Lowell  (near  Tucson),  16;""  Fort  Mohave, 
8;  Gadsden,  4;  Gunsight  (Pima  County),  1;  Hackberry  (Mohave  County), 
1;  Little  Meadows  (east  side  Black  Mountains,  Mohave  County),  1; 
Maricopa  (Pinal  County),  1;  Mellen  (=Topock,  Mohave  County),  5;* 
Mineral  Park  (Mohave  County),  1;  New  River  (30  miles  northwest  of 
Phoenix),  1;  Parker,  7;  Phoenix,  10;  Picachio  Reservoir  (17  miles  south- 
west of  Florence),  1;  Quartzsite  (Yuma  County),  2;  Quitobaquito  (Pima 
Coimty),  4-  Rillito  (10  miles  north,  Pima  County),  2;"  Rillito  Creek 
(5  miles  north  of  Tucson),  1;  Sabinos  Canyon  (Pima  County),  3;"  Santa 
Rita  Range  Reserve,  6;  Santa  Rita  Mountains  (west  base),  1;®  Tempe,  3;' 
Texas  Hill  (Yuma  Coimty),  3;  Tinajas  Desert  (Yuma  County),  1;  Tucson, 
19;  Vicksburg  (Yuma  County),  2;  Well  ton  (Yuma  County),  5;  Wickenburg, 
2;  Yuma,  60. 

Sonora:  Altar  (20  miles  north),  1;"  Batamotal,  6;  Camoa  (Rio  Mayo),  2; 
Cienega  Well  (30  miles  south  of  Monument  no.  204),  1;  Costa  Rica  Ranch, 
1;  Bl  Doctor,  7;"  Guaymas,  2;"  Hermosillo,  15;  Libertad  (50  miles  north- 
east), 2;"  Obregon,  1;"  Ortiz,  48;  Pitiquito,  1;"  Querobabi,  1;"  Rancho 
Oarrizo,  2." 

CITELLUS  TERETICAUDUS  CHLORUS  ErxiOT 

Palm  Springs  Ground  Squirrel 

Citellus  cMorus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3 :  242,  1903. 
Citellus  tereticaudus  chlorus  Grinnell,  Calif.  Acad.  Sci.  Proc.  (4)  3:347,  1913. 

Type. — Collected  at  Palm  Springs,  Riverside  County,  Calif.,  Febru- 
ary 16,  1903,  by  Edmund  Heller;  male  adult,  skin  and  skull,  no. 
12861,  Field  Museum  of  Natural  History. 

'  Mus.  Vert.  Zool. 

8  Field  Mus.  Nat.  Hist. 

1"  D.  R.  Dickey  collection. 

11  Univ.  Michigan  Mus.  Zool. 

12  California  Inst.  Tech. 


lyss]  REVISION  OF  THE  GROUND  SQUIRRELS  189 

Range. — Northwestern  arm  of  the  Colorado  Desert,  specifically, 
the  Coachella  Valley  from  Mecca  northwest  to  Cabazon  (Grinnell 
and  Dixon,  1918,  p.  674)  (fig.  19).    Zonal  range:  Lower  Sonoran. 

External  characters. — Similar  to  G .  t.  tereticaudus  but  coloration 
more  drabby  (less  pinkish). 

Cranial  charaxiters. — Practically  the  same  as  in  tereticaudus. 

Color. — Winter  pelage  (September  27-April)  :  Upper  parts  uni- 
form light  drab,  sometimes  with  a  slight  tinge  of  pinkish  cinnamon ; 
under  parts  white  or  creamy  white ;  sides  of  nose  grayish  white ;  front 
feet  buffy  white;  hind  feet  white;  tail  above,  like  back  on  proximal 
half,  the  distal  half  shaded  with  fuscous  and  edged  with  grayish 
white;  tail  beneath,  light  drab.  Summer  pelage:  Upper  parts  near- 
est to  ecru  drab  of  Ridgway ;  this  pelage  is  short  and  much  harsher 
than  the  winter  pelage,  which  is  soft  and  silky. 

Molt. — The  summer  pelage  is  acquired  usually  in  March  or  April ; 
a  specimen  from  Agua  Caliente,  taken  April  11,  1894  is  in  badly 
worn  condition,  and  shows  the  new  pelage  covering  the  head  and 
throat,  an  irregular  patch  on  the  rump,  and  smaller  patches  on  the 
belly ;  one  from  Whitewater,  April  21,  1894,  shows  new  pelage  cover- 
ing the  entire  under  parts  and  the  anterior  two-thirds  of  the  upper 
parts.  A  breeding  female  from  the  same  locality,  June  3,  1908,  is  in 
a  moderately  worn  drab  pelage,  apparently  the  left-over  winter 
pelage.  Other  specimens  taken  April  3  and  10  are  in  complete  sum- 
mer pelage.  The  tail  is  renewed  last ;  specimens  taken  at  Mecca,  April 
24,  show  the  new  hair  on  the  basal  portion  of  the  tail,  while  others 
taken  at  the  same  dates  have  the  entire  tail  renewed.  Winter  pelage 
is  apparently  acquired  in  September ;  a  specimen  from  Palm  Springs 
September  27,  is  in  complete  fresh  winter  pelage. 

Measurements. — Average  of  10  adults  (7  males,  3  females)  from  Palm  Springs 
and  Whitewater:  Total  length,  243.3  (232-255)  ;  tail  vertebrae,  93.2  (84-100)  ; 
hind  foot,  36.4  (35-40).  Ulcull:  Average  of  11  adults  (8  males,  3  females) 
from  type  locality:  Greatest  length,  36  (35.1-37);  zygomatic  breadth,  22.2 
21.4-23.9)  ;  breadth  of  cranium,  17.6  (17.2-18.2)  ;  interorbital  breadth,  8.6 
(8.1-9.5)  ;  postorbital  constriction,  12.7  (12.2-13.3)  ;  length  of  nasals,  11.2 
(10.7-11.7)  ;  maxillary  tooth  row,  7.3  (7.2-7.6). 

Remarks. — The  color  characters  separating  this  race  from  typical 
tereticaudus  are  slight,  but  fairly  constant.  Writing  of  this  form, 
Grinnell  and  Dixon  (1918,  p.  674)  say: 

The  slight  features  by  which  this  subspecies  is  distinguishable  from  the 
Yuma  Round-tailed  Ground  Squirrel  of  the  Imperial  Valley  southeast  of  Salton 
Sea  may  be  inferred  to  have  arisen  as  a  result  of  the  action  of  the  body  of 
water  which  formerly  filled  the  Salton  Sink  to  sea  level  in  cutting  off  or  isolat- 
ing the  animals  in  the  northwestern  arm  of  the  Colorado  Desert  and  thus  giv- 
ing them  a  chance  to  develop  peculiarities  of  their  own. 

Specimens  examined. — ^Total  number,  91,  as  follows: 

California:  Agua  Caliente  (Riverside  County),  10;  Andreas  Canyon,  San  Jacinto 
Mountains,  1;  Cabazon  (Riverside  County),  1;  Coachella  (Riverside 
County),  1;"  Mecca  (Riverside  County),  18;"''  Palm  Spring.s,  38;""" 
18 17 18  Whitewater  Station  (Riverside  County),  22."" 


"D.  R.  Dickey  collection. 

"Mus.  Vert.   Zool. 

"  Univ.  Michigan  Mus.  Zool. 

'"Acad.  Nat.  Sci.  Philadelphia. 

"  Field  Mus.  Nat.  Hist. 

^^  Los  Angeles  Mus. 


190  NORTH  AMERICAN  FAUNA  [No.  56 

CITBLLUS  TERETIOAUDUS  APRICUS  Huey 

Tkinidad  Valley  Geound  Sqtjibeel 

Citellus  tereticaudus  apricus  Huey,   San  Diego   Soc.  Nat.  Hist.   Trans.  5 :  85, 
Oct.  10,  1927. 

Type. — Collected  in  Valle  de  la  Trinidad,  Baja  California,  Mexico 
(lat.  31°20'  north;  long.  115°40'  west),  by  L.  M.  Huey,  July  13, 
1927 ;  male  adult,  skin  and  skull,  no.  6308,  San  Diego  Soc.  Nat.  Hist. 

Range. — Known  only  from  the  type  locality,  Trinidad  Valley,  Baja 
California  (fig.  19).    Zonal  range:  Lower  Sonoran. 

External  characters — Similar  to  C.  t.  tereticaudus  but  slightly 
darker  (more  brownish). 

Cranial  characters. — Skull  similar  to  that  of  tereticaudus  but 
averaging  longer,  with  relatively  longer  nasals. 

Color  (July  specimens). — Upper  parts  nearly  uniform  cinnamon 
drab ;  sides  of  nose  and  face  washed  with  fuscous ;  feet  buffy  white ; 
tail  above,  cinnamon  drab  at  base,  the  distal  half  fuscous  tipped  with 
pale  buff;  tail  beneath,  pale  pinkish  buff;  under  parts  white. 

Measurements. — Average  of  7  adults  and  3  subadults  {fide  Huey)  :  Total 
length,  244.4  (240-260);  tail  vertebrae,  90.3  (83-98);  hind  foot,  37  (35-39). 
Skull:  Average  of  17  adults  (7  males,  10  females)  :  Greatest  length  37.5 
(36.3-38.5)  ;  palatilar  length,  17.2  (17-18)  ;  zygomatic  breadth,  22.9  (21.8-23.9)  ; 
cranial  breadth,  17.9  (17.3-18.5)  ;  interorbital  breadth,  8.7  (8-9.3)  ;  postorbital 
constriction,,  13  (11.7-13.6)  ;  length  of  nasals,  12.6  (11.9-13.2)  ;  maxillary  tooth 
row,  7.8  (7.2-8.2). 

Remarhs. — This  subspecies  is  a  slightly  differentiated  form  living 
in  a  narrow  valley  at  the  north  end  of  the  San  Pedro  Martir  Range, 
at  an  elevation  of  about  2,500  feet,  on  the  Pacific  slope  (Huey,  1.  c.) ; 
the  limits  of  its  range  are  not  known. 

Specimens  examined. — Total  number,  28,  from  type  locality.^^ 

Subgenus  CALLOSPERMOPHILUS  Merriam 

[Characters  on  p.  45] 
COLOR  PATTERN 

In  most  forms  of  this  gToup  the  color  pattern  consists  of  a  longi- 
tudinal white  stripe  on  each  side  of  the  back,  bordered  on  each  side 
by  a  black  stripe ;  in  some  races  the  inner  black  stripes  are  absent  or 
much  reduced  in  extent  and  the  outer  black  stripes  may  also  be  re- 
duced. Most  of  the  races,  in  summer  pelage,  have  a  more  or  less  dis- 
tinct "mantle"  covering  the  head  and  shoulders,  varying  in  color  from 
cinnamon  buff  to  tawny  or  russet;  the  median  dorsal  area  is  some 
shade  of  gray,  buff,  cinnamon,  or  fawn. 

PELAGE    AND    MOLT 

The  pelage  is  dense  and  soft,  the  bases  of  the  hairs  plumbeous. 

Apparently  there  is  but  one  molt  annually,  occurring  usually  dur- 
ing June  or  the  first  half  of  July,  but  in  some  cases  not  until  the  mid- 
dle of  August.  By  the  following  spring,  the  pelage  often  shows  a 
considerable  amount  of  wear  and  the  rich  colors  of  the  head  and 
shoulders  often  have  faded  to  a  much  paler  shade,  so  that  specimens 

19  Twentj'-six  in  collection  San  Diego  Soc.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  191 

in  this  condition  present  a  very  different  appearance  from  those  in 
fresh  pelage.    No  evidence  of  a  molt  in  the  fall  has  been  discovered. 

Key  to  Species  and  Subspecies 

(Based  on  typical  adults  in  summer  pelage) 

o\  Median  pair  of  dark  dorsal  stripes  prominent. 

b\  Under  side  of  tail  paler  (cinnamon  buff  or  pinkish  cinnamon). 

c\  Mantle  darker  and  more  extensive tescorum  (p.  199) 

c^.  Mantle  paler  and  less  extensive cinerascens  (p.  198) 

b^.  Under  side  of  tail  darker  (tawny  or  russet), 
c^.  Mantle  darker   (russet). 

(Z\  Rump  darker  (natal  brown) trinitatis  (p.  211) 

d^  Rump  paler  (army  brown  or  fawn  color). 
e\  Color  of  mantle  extending  to  the  fore  back. 

f.  Dorsal  area  smoke  gray mitratus  (p.  210) 

f.  Dorsal  area  fawn  color cormectens  (p.  205) 

e^.  Color  of  mantle  not  extending  to  the  fore  back —  caslanurus  (p.  201) 
(f.  Mantle  paler  (ochraceous  tawny  or  mikado  brown). 
d\  Hind  feet  huffy. 

e\  Under  parts  huffy chrysodeirus  (p.  203) 

e^.  Under  parts  whitish bernardmvs  (p.  209) 

d^.  Hind  feet  whitish. 

e^.  Tail  paler  beneath   (tawny). 

f.  Head  darker  (hazel) trepidus  (p.  206) 

H  Head  paler  (mikado  brown) caryi  (p.  197) 

e^.  Tail  darker  beneath  (russet) certus  (p.  208) 

a'.  Median  pair  of  dark  dorsal  stripes  absent  or  much  reduced. 
6^.  Tail  more  than  70  mm. 
c^.  Size  larger  (hind  foot,  43-40  mm)  ;  under  parts 

darker saturatus  (p.  212) 

<f.  Size  smaller  (hind  foot,  4CM4  mm)  ;  under  parts  paler. 

<f\  Upper  parts  paler  (light  pinkish  cinnamon) wortmani  (p.  195) 

(Z^  Upper  parts  darker  (pinkish  cinnamon  or  fawn). 

e\  Tail  paler  beneath lateralis  (p.  191) 

e^.  Tail  darker  beneath arizovensis  (p.  196) 

&2.  Tail  less  than  70  mm niadrcnsis  (p.  213) 

CITELLUS  LATERALIS   (Say) 
[Synonymy   under  subspecies] 

Specific  characters. — Size  small  to  medium;  hind  foot,  35-46  mm; 
tail,  63-118;  skull  length,  39.6-45.6.  Color  pattern  as  usual  in  the 
subgenus  (see  p.  190),  but  coloration  variable.  Except  for  size  and 
proportions,  there  are  no  characters  to  separate  lateralis  from  the  two 
outlying  species — C.  saturatvs  and  C.  madrensis — and  if  the  ranges 
of  these  adjoined  the  range  of  any  of  the  races  of  lateralis^  they  would 
pi'obably  be  found  to  intergrade  with  the  latter. 

There  are,  however,  two  groups  in  the  species  lateralis.,  one  group 
containing  the  subspecies  lateralis.,  arizonensis,  and  tvortmani,  char- 
acterized by  the  absence  or  reduced  extent  of  the  inner  pair  of  dark 
dorsal  .stripes,  and  the  other  group,  comprising  the  remaining  11 
races,  in  which  these  stripes  are  prominent. 

CITELLUS   LATERALIS  LATERALIS    (Say) 

S.\y's  Mantled  Ground  Squirrel 

(PKs.   27,   D;  32,  D) 

8[ciurus'\  lateralis  Say,  Long's  Exped.  Rocky  Mountains,  2:  46,  1823. 
Arctomys   (Spermophilus)   lateralis  Richardson,  Zool.  Jour.  3:  519,  1828. 
Bpcrtnophilus  lateralis  F.  Cuvier,  Sup.  ^  I'hist.  natur.  Buffon,  Mamm.  1:  335, 

1831. 


192 


NORTH  AMERICAN  FAUNA 


[No.  56 


Tamias  lateralis  Allen,  Boston  Soc.  Nat.  Hist.  Proc.  16:  290,  1874. 
GallospermopMlus  lateralis  Merriam,  Wash.  Acad.  Sci.  Proc.  3:  563,  1901. 
Citellus    (Callospermophilus)    lateralis  Allen,   Brooklyn  Inst.   Mus.,    Sci.   Bull. 
1:  119,  1905. 

Type. — None  designated;  description  apparently  based  on  a  speci- 
men taken  by  Long's  Expedition  on  the  Arkansas  Eiver  near  Canon 

City,.  Colo.;  a  speci- 
men said  to  be  "pre- 
served in  the  Phila- 
delphia Museum." 
(Say,  1823,  p.  47.) 

Rang  e. — South- 
central  Wyoming, 
central  and  western 
Colorado,  eastern 
Utah,  northern  Ari- 
zona, and  northern 
New  Mexico;  north 
to  southern  Fremont 
County,  Wyo.  (Min- 
ers Delight)  ;  east  to 
the  foothills  of  the 
Rocky  Mountains  in 
Colorado  and  New 
Mexico ;  south  to  San 
Miguel  County,  N. 
Mex.  (upper  Pecos 
River)  ;  west  to  the 
Beaver  Mountains, 
Utah,  and  the  Kai- 
bab  Plateau,  Ariz. 
(fig.  20).  Zonal 
range:  Transition, 
Canadian,  and  Hud- 
sonian. 

External  charac- 
ters. —  Head  and 
face  mikado  brown 
or  pinkish  cinnamon 
(paler  than  in  G.  I. 
castanurus  and  G.  I. 
cinerascens) ;  shoul- 
ders tawny;  mantle 
not  well  defined ; 
inner  pair  of  black 
dorsal  stripes  obso- 
lete or  much  re- 
duced ;  under  side  of 
tail  pinkish  buff  or 
pinkish  cinnamon 
(similar  to  that  of 
cinerascens) . 
Granial  characters. — Skull  about  the  size  of  that  of  cinerascens; 
nasals  longer,  extending  considerably  beyond  the  posterior  border  of 
the  premaxillae. 


Figure  20. — Distribution  of  Citellus  saturatus  and  C.  mad- 
rensis  and  of  tlie  subspecies  of  C  lateralis  (subgenus  Cal- 
lospermophilus) :  1,  C.  I.  tescorum;  2,  C.  saturatus,  3, 
C.  I.  connectens;  4,  C.  I.  ch/rysodeirus ;  5,  C.  I.  trinitatis; 
6,  C.  I.  mitratus;  7.  G.  I.  trepidus;  8,  C.  I.  cinerascens; 
9,  C.  I.  caryi;  10,  C.  I.  castanurus ;  11,  O.  I.  wortmani; 
12,  C.  I.  lateralis;  13,  C.  I.  arizonensis ;  14,  C.  I.  certus; 
15,  C.  I.  bernardinus;  16,  C.  madrensis. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  193 

Color. — Summer  pelage  (Specimens  from  Boulder  and  Estes  Park, 
Colo. )  :  Head  and  face  pinkish  cinnamon  or  mikado  brown ;  eye  ring 
buffy  white;  shoulders  and  sides  of  neck  tawny,  mikado  brown,  or 
cinnamon;  ears  pinkish  cinnamon,  margined  with  pale  buff;  dorsal 
area  pinkish  cinnamon,  more  or  less  mixed  with  light  smoke  gray 
(the  gray  sometimes  predominating) ;  rump  and  thighs  fawn  color; 
lateral  stripes  creamy  white  or  pinkish  buff,  bordered  beneath  by  a 
shorter  black  stripe;  lower  sides  from  shoulders  to  rump,  pinkish 
buff  or  pale  pinkish  buff;  feet  creamy  white  or  pinkish  buff;  tail 
above,  fuscous  black,  mixed  with  pinkish  buff  or  pinkish  cinnamon; 
tail  beneath,  pinkish  buff  or  pinkish  cinnamon ;  under  parts  creamy 
white  or  pale  pinkish  buff.  Winter  pelage  (Specimens  from  Lake 
City,  Colo.,  Sept.  17;  Bridger  Pass,  Wyo.,  May  9)  :  Shoulders  and 
sides  of  neck  pinkish  buff,  more  or  less  mixed  with  cinnamon  and 
fuscous ;  otherwise  about  as  in  summer  pelage. 

Molt. — The  molt  takes  place  usually  in  June  and  July ;  a  male  speci- 
men from  Boulder,  Colo,  June  11,  shows  new  pelage  covering  the 
head,  shoulders,  and  most  of  the  back  and  under  parts,  the  lower 
sides,  rump,  and  hinder  back  still  retaining  the  old  worn  winter 
pelage;  a  male  from  Cascade,  Colo.,  June  28,  has  nearly  completed 
the  spring  molt;  another  male  from  Coulter,  Colo.,  July  10,  shows 
new  pelage  covering  the  anterior  two-thirds  of  the  body,  the  re- 
mainder being  in  badly  worn  winter  pelage.  In  young  individuals 
and  breeding  females,  the  molt  is  often  delayed  until  August;  two 
immature  specimens  from  Estes  Park,  Colo.,  taken  on  July  30  and 
August  27,  respectively,  shoAv  new  pelage  covering  the  anterior  half 
of  the  body;  an  adult  female  from  Hermit,  Colo.,  July  31,  is  still  in 
worn  winter  pelage,  except  for  small  patches  of  fresh  hair  on  the 
head;  another  breeding  female  from  Estes  Park,  August  12,  shows 
a  molt  beginning  on  the  head  and  the  middle  of  the  back. 

Measurements. — Average  of  10  adnlt  males  from  Colorado  and  nortberu  New 
Mexico:  Total  length,  273  (254-292);  tail  vertebrae,  92  (81-107);  bind  foot, 
42.6  (41^4)  ;  ear  from  notcb  (dry),  14.4  (14-15).  Average  of  10  adult  females 
from  same  localities:  Total  length,  275  (252-293)  ;  tail  vertebrae,  95.8  (83-106)  ; 
bind  foot,  41.5  (40-43)  ;  ear  from  notcb,  14.5  (13-16).  Skull:  Average  of  10 
adult  males  from  Colorado  and  northern  New  Mexico :  Greatest  length,  43.9 
(42.9^5.5)  ;  palatilar  length,  20.2  (19.5-21)  ;  zygomatic  breadth,  27.3  (26.2^ 
27.9)  ;  cranial  breadth,  20  (19.3-20.5)  ;  interorbital  breadth,  10.5  (10-11.1)  ; 
postorbital  constriction,  12.7  (12-13.4)  ;  length  of  nasals,  16.4  (15.1-17.5)  ;  max- 
illary tooth  row,  8.6  (8.3-9.4).  Average  of  10  adult  females  from  same  region: 
Greatest  length,  43.3  (42.1-44.4)  ;  palatilar  length,  20.1  (19.5-20.5)  ;  zygomatic 
breadth,  27.3  (26.3-28.3)  ;  cranial  breadth,  19.9  (19.3-20.3)  ;  interorbital  breadth, 
10.2  (9.6-11.3)  ;  postorbital  constriction.  12.7  (11.8-13.5)  ;  length  of  nasals, 
15.9  (15.2-17)  ;  maxillary  tooth  row,  8.4  (7.8-9.2). 

Weight. — Hatt  (1927,  p.  3)  gives  the  average  weight  of  5  males  as  242.4 
g   (212-275)   and  of  5  females  as  220.2  g  (167-264). 

Remarks. — Say's  ground  squirrel,  the  first  member  of  the  group 
to  be  discovered,  has  a  wide  range  in  the  southern  Rocky  Mountain 
region  and  westward  over  a  large  part  of  Utah.  With  the  subspecies 
wortmani  and  arizonensis  it  forms  a  well-marked  group,  character- 
ized by  a  rather  dull-colored  mantle,  and  partial  or  complete  sup- 
pression of  the  interior  pair  of  black  dorsal  stripes.  It  differs  widely 
in  these  characters  from  G.  I.  castanums  and  no  intergrades  between 
the  two  are  known ;  however,  intergradation  with  C.  I.  caryi  is  clearly 
shown  by  a  series  of  four  specimens  from  Big  Sandy,  Wyo.;  three 

154970—38 13 


j^g^  ,  NORTH  AMERICAN  FAUNA  [No.  56 

of  these  resemble  lateralis  in  the  color  of  the  under  surface  of  the 
tail,  but  differ  in  having  the  inner  pair  of  black  stripes  well-developed 
in  two  individuals,  shorter  in  the  other  two;  their  skulls  are  large, 
agreeing  with  those  of  lateralis.  Thus  the  two  groups — lateralis  and 
chrysodeirus — long  supposed  to  be  distinct,  are  now  shown  to  consist 
of  a  single  species,  separable  into  14  races. 
Specimens  examined. — Total  number,  295,  as  follows: 

Arizona:  Kaibab  National  Forest,  23  (V.  T.  Park,  17;  Jacob  Lake,  4;  Green- 
land Spring,  2)  ;  Fort  Defiance  (12  miles  northwest,  at  7,800  feet  altitude), 
4;  Lukachukai  Mountains,  13;  Tunitclia  Mountains,  12. 

Colorado:  Boulder,  3;  Boulder  County,  6;  Boulder  Pass,  1;  Buckhorn  Ranger 
Station,  2;  Buena  Vista,  2f  California  Gulch,  1;  Cascade  (El  Paso  County), 
4;  Castle  Rock  (10  miles  southwest),  4;''°  Coulter,  2;  Dayton  (on  Twin 
Lakes),  2;  Douglas  Spring  (Routt  County),  5;"^  Elk  Mountains,  1;  Esca- 
lante  Hills  (20  miles  southeast  of  Lodore),  1;  Estes  Park,  18;  Evergreen, 
1;  Garo  (Park  County),  1;  Gold  Hill,  7;  Hahns  Peak  (Roiitt  County),  1; 
Hermit  (San  Juan  County),  2;  Idaho  City  (=Idaho  Springs),  4;  Jeffer- 
son County,  1;  Lake  City,  2;  La  Veta,  1;'"  Longs  Peak,  5;  Manitou,  3;'° 
Marvine  (Rio  Blanco  County),  1;  Mears  (Chaffee  County),  1;^^  Meeker, 
1;  Monshower  Meadows  (3  miles  west  of  Cochetopa  Pass),  1;  North  Park, 
2;  Pagosa  Springs,  3;  Pearl  (Jackson  County),  1;  Pikes  Peak  (10,000 
feet  altitude),  1;  Rabbit  Ear  Mountains  (Grand  County),  3;  Rangely  (Rio 
Blanco  County),  1;  Rifle,  1;  Rio  Blanco  (Rio  Blanco  County),  2;  Saguache 
Park,  1 ;  Steamboat  Springs  (15  miles  west),  1 ;  Toponas,  1  f^  Ward  (Boulder 
County),  1;  Westclifte  (Custer  County),  1;  White  River  (20  miles  east  of 
Rangely),  1. 

New  Mexico:  Baldy  Mountain  (Colfax  County),  I;'"  Catskill  (Colfax  County), 
1;  Chu.ska  Mountains,  4;  Cimarron  (Colfax  County),  2;"  Costilla  Pass 
(Colfax  County),  2;  Coyote  Creek  (8,400  feet  altitude.  Mora  County),  1; 
Halls  Peak  (Mora  County),  1;  Hondo  Canyon  (Santa  Fe  County),  5;  Hope- 
well (8  miles  west,  Rio  Arriba  County),  1;  Jemez  Mountains,  3;  Long 
Canyon  (3  miles  north  of  Catskill,  Colfax  County),  3;  Martinez  (Colfax 
County),  1;  Pecos  (10  miles  north),  1;  Pecos  Baldy  (12,000  feet  altitude), 
2;  Pajado  Canyon  (Colfax  County),  1;  Red  River  (Taos  Coimty),  1  ;^* 
Santa  Fe,  1 ;  Santa  Fe  Canyon,  2  f  Taos  Mountains,  1 ;  Tierra  Amarilla, 
1;  Tres  Piedras  (Taos  County),  13;  Willis  (near  Cowles,  San  Miguel 
County),  5. 

Utah:  Beaver  Creek  (4  miles  south  of  Lonetree,  Wyo.),  2;  Beaver  Mountains, 
21  (Britts  Meadows,  17;^*  Mount  Delano,  1;  Petty  Mountain  (15  miles 
north  of  Mountain  Home),  1;"  Puffer  Lake,  2;  Currant  Creek,  Uinta  Na- 
tional Forest,  1 ;  Ephraim,  4 ;  Fish  Lake  National  Forest,  3  f^  Junction  of 
Green  and  White  Rivers,  3;°^  Manila  (10  miles  southeast),  1;^^  Parowan 
Mountains  (Brian  Head),  1;  Uinta  Mountains,  Gilbert  Peak  (10,000  feet 
altitude),  1;  Uinta  Mountains  (Daggett  County),  15 ; '"  Vernal,  4;  '="  White- 
rocks,  1. 

Wyoming:  Big  Sandy,  4;  BridgerPass  (Carbon  County),  3;  Islay  (6  miles  west, 
Laramie  Coimty),  1;  Laramie  Mountains,  1;  Maxon  (Sweetwater  County), 
1;  Medicine  Bow  Mountains,  2;  Miners  Delight  (3  miles  northeast  of  At- 
lantic City,  Fremont  County),  1;  Pole  Mountain  (15  miles  southeast  of 
Laramie),  3;  Sherman  (Albany  County),  1;""  Sierra  Madre  Mountains 
(south  base  Bridger  Peak),  3;  South  Pass  City  (6  miles  north,  Fremont 
County),  1;  Springhill  (12  miles  north  of  Laramie  Peak),  2;  Woods  P.  O- 
(4  miles  north  of  Jelm,  Albany  County),  5. 

2"  Univ.  Michigan  Mus.  Zool. 

-1  B.  R.  Warren  collection. 

2=  Cleveland  Mus.  Nat.  Hist. 

23  Three  in  Amer.  Mus.  Nat.  Hist.,  four  in  Mus.  Vert.  Zool. 

2^  Utah  State  Agr.  CoUege. 

25  Mus.  Vert.  Zool. 

28  Amer.  Mus.  Nat.  Hist. 

"  Carnegie  Mus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  195 

CITELLUS  LATERALIS  WORTMANI    (Allen) 

Wortman's  Mantled  Ground  Sqtjirrei- 

Tamias  wortmani  Allen,  Amer.  Miis.  Nat.  Hist.  Bull.  7 :  335.  Nov.  8,  1895. 
[Sperniophilus]  icortmuni  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  2:84,  1901. 
Citellus  wortmani  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6:  107,  1905. 
CallospennophiUis  ivortmani  Gary,  Biol.  Soc.  Wash.  Proc.  20:  86,  1907. 
CaUospermophilus  lateralis  ivortmani  Gary,  North  Amer.  Fauna  33:  84,  1911. 

Type. — Collected  at  Kinney  Ranch,  Bitter  Creek,  Sweetwater 
County,  Wyo.,  July  13, 1895,  by  Walter  W.  Granger ;  male  adult,  skin 
and  skull,  no.  VsV/?  Amer.  Mus.  Nat.  Hist. 

Range. — Deserts  and  badlands  in  south-central  Wyoming  and 
northwestern  Colorado;  north  to  Steamboat  Mountain,  Sweetwater 
County,  Wyo. ;  south  to  Bear  River  Valley,  Routt  County,  Colo.  (fig. 
20).    Zonal  range:  Upper  Sonoran. 

External  characters. — Similar  to  C.  I.  lateralis  but  of  paler  colora- 
tion. Compared  with  C.  I.  caryi:  Inner  pair  of  black  dorsal  stripes 
absent  or  very  faintly  indicated;  colors  paler,  especially  of  the  head, 
shoulders,  and  under  side  of  tail. 

Cranial  characters. — Skull  closely  similar  to  that  of  lateralis.^  but 
averaging  slightly  larger,  except  the  nasals,  which  are  shorter. 

Color. — Summer  pelxige:  Top  of  head  pinkish  cinnamon  or  vina- 
ceous  cinnamon;  eye  ring  buffy  white;  stripe  beneath  the  eye  reach- 
ing to  the  ear,  sayal  brown ;  ears  cimiamon,  shading  to  pinkish  buff 
on  posterior  border;  shoulders  and  sides  of  neck  cinnamon;  sides 
of  nose  and  lower  cheeks  pinkish  buff;  dorsal  area  pinkish  buff  or 
light  pinkish  cinnamon,  faintly  shaded  with  fuscous  (the  bases  of 
the  hairs  fuscous) ;  lateral  stripes  pinkish  buff,  bordered  beneath 
with  a  shorter  black  stripe,  which  latter  is  sometimes  partly  ob- 
scured by  cinnamon;  lower  sides  pinkish  buff;  rump  same  color  as 
the  back ;  thighs  cinnamon  buff  or  mikado  brown ;  feet  pinkish  buff ; 
tail  above,  fuscous  black,  mixed  with  pinkish  buff;  tail  beneath,  warm 
buff;  under  parts  pinkish  buff. 

Molt. — The  summer  molt  occurs  in  July;  an  adult  male  taken  on 
Bitter  Creek,  Wyo.,  July  7,  had  nearly  completed  the  molt,  new 
pelage  covering  the  anterior  portion  of  the  body  and  the  tail,  leav- 
ing the  rump  with  the  old  worn  j^elage ;  adult  females  taken  July  5, 
and  9,  are  in  badly  worn  winter  pelage  with  a  small  patch  of  new 
hair  appearing  in  the  middle  of  the  back. 

Measurements. — Average  of  0  adults  (2  males,  4  females)  from  type  locality: 
Total  length,  280  (271-289)  ;  tail  vertebrae,  95  (87-101)  ;  hind  foot,  43.2  (41- 
44)  ;  ear  from  notch  (dry),  17.1  (16-18).  Sknll ;  Average  of  (5  adults  (2  males, 
4  females):  Greatest  length,  44.1  (43.4-46);  palatilar  length,  20.4  (20-21); 
zygomatic  breadth.  27.0  (27.4-28.5)  ;  cranial  breadth,  20.4  (20.2-20.7)  ;  inter- 
orbital  breadth,  10.3  (9.0-10.0)  ;  postorbital  constriction,  13  (12.5-13.8)  ;  length 
of  nasals,  15.6  (15.2-16.2)  ;  maxiUary  tooth  row,  8.7  (8.3-9.1). 

Remarks. — This  pale  race  is  confined  to  a  rather  restricted  area 
of  desert  country,  and  its  range  is  almost  entirely  surrounded  by  the 
range  of  lateralis. 

Specimens  examined . — Total  num.ber,  50,  as  follows : 

Colorado:  Snake  River  (5-7  miles  above  Lily),  5;  ^  Snake  River  (20  miles  below 

Baggs,  Wyo.),  1. 
Utah:  Uncorapahgre  Indian  Reservation,  1.^° 
Wyoming:  Bitter  Creek  (Kinney  Ranch,  Sweetwater  County),  42;  ™  Superior,  1. 


=*  E.  R.  Warron  collection. 
^  Amer.  Mus.  Nat.  Hist. 


IQQ  NORTH  AMERICAN  FAUNA  [No.  56 

CITELLUS  LATERALIS  ARIZONENSIS   (Baujst) 
Aeizona  Mantled  Ground  Sqxjierbl 

CallospermopMlus    lateralis    arizoncnsis    Bailey,    Biol.    Soc.    Wash.    Proc.    26 : 

130,  May  21,  1913. 
Citellus  lateralis  arizonensis  Elliot,  Check-list  Mamm.  North  Amer.,   Sup.,  p. 

30,  19J7. 

Type. — Collected  near  Little  Spring,  San  Francisco  Mountain, 
Ariz,  (altitude  8,250  feet),  August  8,  1889,  by  C.  Hart  Merriam  and 
Vernon  Bailey;  male  adult,  skin  and  skull,  no.  |I|^|,  U.  S.  Natl. 
Mus  (Biological  Survey  collection)   (orig.  no.  308). 

Range. — ^Mountains  and  high  plateaus  in  central  and  eastern 
Arizona  and  west-central  New  Mexico;  north  to  San  Francisco 
Mountain,  Ariz.;  east  and  south  to  the  Mimbres  Mountains,  N. 
Mex.  (fig.  20).    Zonal  range:  Transition  and  Canadian. 

External  characters. — Similar  in  summer  pelage  to  0.  I.  lateralis^ 
but  slightly  deeper  colored  on  head  and  thighs ;  tail  grizzled  beneath 
with  blackish  and  usually  lacking  a  clear  yellowish  median  area. 

Cranial  characters. — Skull  closely  similar  to  that  of  lateralis. 

Color. — Summer  pelage:  Top  of  head  and  face  hazel  or  vinaceous 
cinnamon;  shoulders  tawny;  dorsal  area  mixed  pinkish  cinnamon 
and  pale  smoke  gray,  shading  on  rump  and  thighs  to  mikado  brown 
or  russet;  light  dorsal  stripes  from  shoulders  to  hips,  pinkish  buff 
or  warm  buff ;  outer  pair  of  dark  stripes  about  as  broad  as  the  light 
stripes,  but  shorter ;  inner  pair  of  dark  stripes  nearly  obsolete ;  sides 
of  body  and  under  parts  pinkish  buff  or  warm  buff ;  front  feet  and 
legs  cinnamon  or  cinnamon  buff,  shaded  with  pinkish  buff;  hind 
feet  pinkish  buff,  often  washed  with  some  of  the  russet  color  of 
the  legs;  tail  above,  fuscous  black,  mixed  with  ochraceous  buff  or 
pinkish  buff;  tail  beneath,  ochraceous  buff  or  pale  cinnamon  buff, 
more  or  less  mixed  with  fuscous  black.  Winter  pelage  (October  31)  : 
Nose  and  front  of  face  cinnamon;  upper  parts  from  crown  to  rump 
smoke  gray,  shaded  with  pale  buff  on  hinder  back;  thighs  mikado 
brown;  tail  above,  fuscous  black,  mixed  with  pale  pinkish  buff; 
inner  pair  of  black  dorsal  stripes  present  on  middle  of  back,  but 
narrower  than  outer  pair  (which  are  likewise  short) ;  light  dorsal 
stripes  dull  creamy  white;  feet  and  under  parts  creamy  white. 

Molt. — An  adult  female  from  San  Francisco  Mountain,  August  13, 
is  acquiring  a  new  pelage  on  the  head,  shoulders,  and  middle  of  the 
back ;  doubtless  the  molt  begins  earlier  than  that  date  in  most  cases, 
but  with  the  material  at  hand  it  is  not  possible  to  determine  the 
usual  time. 

Measurements. — ^Average  of  17  adults  (10  males,  7  females)  from  type 
locality:  Total  length,  277.6  (265-292)  ;  tail  vertebrae.  98  (90-106)  ;  hind  foot, 
41.7  (40^4);  ear  from  notch  (dry),  14.2  (13-15.5).  Skull:  Average  of 
10  adults  (5  males,  5  females)  from  type  locality:  Greatest  length,  43.8 
(42.9-^4.6)  ;  palatilar  length,  20.1  (19.5-21)  ;  zygomatic  breadth,  27.7  (26.8- 
28.6)  ;  cranial  breadth,  19.8  (19.4-20.7)  ;  interorbital  breadth,  10.6  (10.2-11.5)  ; 
postorbital  constriction,  13.2  (12.6-14.3)  ;  length  of  nasals,  15.9  (15.4^16.8)  ; 
maxillary  tooth  row,  8.4   (8-8.8). 

Weight. — Hatt  (1927,  p.  3)  gives  the  average  weight  of  8  females  as  229.8  g 
(177-270)  ;  two  males  weight  200  and  220  g,  respectively. 

Remarhs. — This  race  is  a  slightly  marked  form,  occupying  an 
area  isolated  from  the  typical  race,  lateralis.. 

Specimens  examined. — Total  number,  120,  as  follows : 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  197 

Arizona:  Alpine  (Apache  County),  4;  "Apache"  (=Ora  Peak),  1;  Baker  Butte 
(Mogollon  Mesa),  7;  Flagstaff,  2U ;  Hart  Prairie  (12  miles  north  of 
Flagstaff),  2;  Little  Spring  (18  miles  northwest  of  Flagstaff),  1;  Monte- 
zuma Well  (Yavapai  County),  1;  Mount  Thomas,  10;  Prioto  Plateau 
(Greenlee  County),  7;  San  Francisco  Mountain,  46;  Sprinserville,  4;  White 
Mountains,  4  (Horseshoe  Cienega,  3;  Marsh  Lake,  1)  ;  Williams,  1. 

New  Mexico:  Mimbres  River  (head),  1;  Mimbres  Mountains  (Big  Rocky  Creek), 
1;  Luna  (Catron  County),  1. 

CITELLUS  LATERALIS  CARYI   (HowEix) 

Caby's  Mantled  Ground  Squikrei, 

Callospefmophilus  lateralis  caryi  Howell,  Biol.  Soc.  Wash.  Proc.  30:  105,  May  23, 
1917. 

Type. — Collected  7  miles  south  of  Fremont  Peak,  Wind  River 
Mountains,  Wyo.  (10,400  feet  altitude),  July  19,  1911,  by  Merritt 
Gary;  female  adult,  skin  and  skull,  no.  176826,  U.  S.  Natl.  Mus. 
(Biological  Survey  collection)   (orig.  no.  2211), 

Range. — ^Wind  Eiver  Mountains,  Wyo.,  and  parts  of  Gros  Ventre 
Range;  north  (apparently)  to  Wildcat  Ridge,  south  of  Yellowstone 
Park  (fig.  20).    Zonal  range:  Canadian  and  Hudsonian. 

External  characters. — Similar  to  C .  I.  castanurus.,  but  paler  and 
more  grayish  on  the  back ;  under  side  of  tail  paler.  Compared  with 
G.  I.  lateralis:  Head  and  shoulders  in  summer  pelage  darker  and 
more  extensively  tawny;  inner  pair  of  black  dorsal  stripes  well  de- 
veloped (nearly  obsolete  in  lateralis) ;  under  side  of  tail  darker 
(tawny  or  clay  color).  Compared  with  C.  I.  cinerascens :  Size  small- 
er; under  side  of  tail  clear  tawny  instead  of  cinnamon  buff. 

Cranial  characters. — Skull  closely  similar  to  that  of  castanurus; 
smaller  than  those  of  lateralis  and  cinerascens. 

Color. — Summer  pelage:  Top  and  sides  of  head  mikado  brown  or 
sayal  brown ;  lower  cheeks  cinnamon  buff ;  eye  ring  white ;  shoulders 
and  sides  of  neck  mikado  brown;  median  dorsal  area,  from  nape  to 
tail,  light  drab,  more  or  less  shaded  with  pinkish  cinnamon  or  pink- 
ish buff;  lateral  stripes  white  or  creamy  white,  reaching  from  the 
ears  to  the  rump,  bordered  above  and  below  by  black  stripes  of  about 
the  same  width,  reaching  from  the  shoulders  nearly  to  the  hips  (the 
inner  pair  shorter  and  sometimes  narrower) ;  lower  sides  pinkish 
buff;  feet  whitish  or  faintly  washed  with  cinnamon  buff;  tail  above, 
black,  more  or  less  mixed  with  cinnamon  buff  or  cartridge  buff;  tail 
beneath,  tawny  or  clay  color,  edged  with  cartridge  buff  or  cinnamon 
buff;  under  parts  creamy  white.  Winter  pelage  (May  16)  :  Head 
fawn  color;  sides  of  neck  pinkish  buff;  back  drab  gray;  rump  and 
thighs  cinnamon  drab;  light  dorsal  stripes  clear  white,  extending 
from  ears  to  rump;  sides  and  under  parts  grayish  white;  otherwise 
as  in  summer  pelage. 

Measurements. — Average  of  8  adults  (2  males,  6  females)  :  Total  length,  273 
(265-282)  ;  tail  vertel)rae,  97  (83-101)  ;  hind  foot,  40.5  (39-42)  ;  ear  from  notch 
(dry),  13.4  (12.5-15).  Skull:  Average  of  3  adult  females:  Greatest  length,  42 
(41.6-42.7)  ;  palatilar  length,  19.2  (19-19.5)  ;  zygomatic  breadth,  25,9  (25.8-20)  ; 
cranial  breadth,  18.8  (18.6-18.9)  ;  interorbital  breadth,  10  (9.7-10.4)  ;  postor- 
bital  constriction,  12.4  (12.1-13.4)  ;  length  of  nasals,  14.4  (13.8-14.7)  ;  maxillary 
tooth  row,  8.5  (8.4-8.7).  One  adult  male  from  Kendall,  Wyo.:  43.6;  20;  26.8; 
18  9  ;  9.5  ;  12.9  ;  15.5 ;  8. 

Remarks. — This  race  has  a  limited  range  between  the  ranges  of 
cinerascens  on  the  north  and  lateralis  on  the  soutli.    Intergradation 


198  NORTH  AMERICAN  FAUNA  [No.  56 

with  lateralis  is  shown  by  a  series  from  Big  Sanely  (referred  to  later- 
alis) ;  there  is  no  evidence  at  present  of  intergradation  with  ciner- 
ascens,  but  doubtless  this  does  occur ;  C.  I.  caryi  is  most  nearly  related 
to  castanurus^  with  which  it  intergrades  in  the  Gros  Ventre 
Mountains. 

Specimens  examined. — Total  number,  12,  as  follows : 

Wyoming:  Bobcat  Ridge  (Teton  County),  2;  Bull  Lake  (Fremont  County),  1; 
Fremont  Peak  (5  miles  south,  10,600  feet),  3;  Jakeys  Creek  (5  miles  south 
of  Dubois),  3;  Lake  Fork  (Wind  River  Mountains,  10,600  feet),  3. 

CITELLUS   LATERALIS   CINERASCENS    (Merriam) 

Mebriam's  Mantled  Ground  >Squirrex 

Tamias  cinerascens  Merriam,  North  Amer.  Fauna  4 :  20,  Oct.  8,  1890. 
Tamias  lateralis  cinerascens  Tliompson  [Seton],  Recreation  8:  365,  May  1898. 
[SpermopMlus]  cinerascens  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  2:  106, 

1901. 
Citellus  cinerascens  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6 :  106,  1905. 
C [allospermophilus]  cinerascens  Warren,  Mamm.  Colorado,  p.  168,  1910. 

Type. — Collected  at  Helena,  Mont.,  August  13,  1888,  by  C.  Hart 
Merriam;  female  adult,  skin  and  skull,  no.  186465,  U.  S.  Natl.  Mus. 
(fi-7T5  Merriam  collection)   (orig.  no.  4). 

Range. — Outlying  ranges  in  south-central  Montana  and  north- 
western Wyoming,  from  Helena  south  to  Yellowstone  Park  and  east 
to  the  Beartooth  Mountains  (fig.  20).  Zonal  range:  Canadian  and 
Hudsonian. 

External  characters. — Similar  to  C.  I.  castanurus.^  but  general  tone 
of  upper  parts  more  grayish  (less  vinaceous) ;  mantle  similar  in 
color  but  sides  of  face  and  neck  more  ochraceous;  tail  much  paler 
beneath  (less  tawny)  ;  hind  foot  longer.  Compared  with  C.  I.  later- 
alis: Upper  parts  more  grayish  (less  vinaceous)  ;  mantle  darker 
(more  tawny) ;  median  pair  of  black  stripes  always  present  and 
equaling  the  outer  pair  in  width;  under  side  of  tail  paler.  Com- 
pared with  C.  I.  tescorum:  Mantle  paler  and  less  extensive;  tail 
averaging  longer,  and  paler  beneath. 

Cranial  characters. — Skull  similar  to  that  of  lateralis  in  size  and 
proportions,  nasals  shorter,  reaching  but  little  beyond  posterior  bor- 
der of  premaxillae ;  decidedly  larger  than  the  skull  of  castanurus  or 
G .  I.  chrysodeirus. 

Color. — Summer  pelage  (topotypes,  August)  :  Top  of  head,  nape, 
and  sides  of  neck  below  and  behind  the  ears  hazel,  bordered  next  the 
throat  with  ochraceous  buff  or  ochraceous  tawny;  sides  of  nose, 
cheeks,  and  eye  ring  pale  pinkish  buff;  dorsal  area  smoke  gray, 
shaded  on  rump  and  thighs  with  mikado  brown ;  lower  sides  pinkish 
buff ;  under  parts  warm  buff  varying  to  pale  pinkish  buff ;  feet  pink- 
ish buff  or  creamy  white;  tail  above,  fuscous  black,  edged  with  cin- 
namon buff;  tail  beneath,  pinkish  buff  or  pale  cinnamon  buff,  bor- 
dered on  sides  and  tip  with  fuscous  black,  and  edged  with  cinna- 
mon buff  or  buffy  white.  Winter  pelage  (adult  female  topotype,  Au- 
gust 13)  :  Mantle  absent;  entire  head,  nape,  back,  and  rump,  smoke 
gray;  dorsal  stripes  as  usual,  sides  ivory  yellow;  tail  much  as  in 
summer,  but  usually  more  mixed  with  blackish,  and  lacking  the  clear 
pinkish  buff  of  the  summer  pelage. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  IQQ 

Molt. — The  molt  evidently  occurs  in  late  summer,  as  indicated  by 
the  presence  of  adult  females  in  winter  pelage  on  August  13  at 
Helena;  a  female  from  Pahaska  Tepee,  Wyo.,  August  3,  shows  new 
summer  pelage  covering  the  head  to  a  line  a  short  distance  back  of 
the  ears. 

Measurements. — Average  of  4  adults  (1  male,  3  females)  from  Yellowstone 
Park  and  vicinity:  Total  length,  286  (270-297)  ;  tail  vertebrae,  107  (95-118)  ; 
hind  foot,  43.6  (41-46)  ;  ear  from  notch  (dry),  14.9  (14-10).  Skull:  One  adult 
male  from  Helena,  Mont.:  Greatest  length,  45.6;  palatilar  length,  21;  zygomatic 
breadth,  28.2 ;  cranial  breadth,  20.4 ;  interorbital  breadth,  11 ;  postorbital  con- 
striction, 12.7 ;  length  of  nasals,  15.6 ;  maxillary  tooth  row,  8.2.  Average  of  4 
adult  females  from  Helena  and  Emigrant  Gulch,  Mont.,  and  Yellowstone  Park, 
Wyo.:  Greatest  length,  43.9  (42.0^5)  ;  palatilar  length,  20.1  (19.3-21)  ;  zygo- 
matic breadth,  27.5  (26.3-29.3)  ;  cranial  breadth,  20.1  (19.3-20.8)  ;  interorbital 
breadth,  105  (10.2-11)  ;  postorbital  constriction,  13.3  (12.9-13.7)  ;  length  of 
nasals,  14.9   (14.5-15.5);   maxillary  tooth  row,  8.9    (8.7-9.2). 

Reinarhs. — This  race  is  most  nearly  related  to  tescorum^  but  differs 
from  it  in  the  paler  color  of  the  mantle  and  in  the  slightly  longer  tail, 
which  is  clearer  yellow  beneath.  The  series  available  from  the  type 
locality  is  inadec{uate  to  show  the  range  of  variation  in  summer 
pelage  and  the  exact  limits  of  range  of  the  subspecies  are  still  to  be 
worked  out  after  more  thorough  collecting  in  Montana. 

Specimens  examined. — Total  number  28,  as  follows : 

Montana:  Beartooth  Mountains,  2;  Butte  (12  miles  east),  0;  Deer  Lodge 
County,  3;^"  Emigrant  Gulch  (near  Emigrant  Peak,  Park  County),  1; 
Helena,  8. 

Wyoming:  Pahaska  Tepee  (Whirlwind  Peak),  3;  I'ellowstone  Park,  5. 

CITELLUS  LATERALIS  TESCORUM   (Hollisteb) 

HoLLISTEIl'S    IMANTLED    GkOUND    SQTJIRREa:. 

Citellus   iCallospennophilus)   ciucrascens  Preble,  North  Amer.  Fauna  27:  166, 

1908  (not  of  IMerriam). 
Callospennophilus  lateralis  tescorum  Hollister,  Smithsn.  Misc.  Collect.  50  (26)  : 

2,  Dec.  5,  1911. 
C  Hell  us  lateralis  tescorum  Elliot,  Check-list  Mamm.  North  Amer.   Sup.,  p.  29, 

1917. 

Type. — Collected  at  head  of  Moose  Pass  Branch  of  the  Smoky 
River,  All)erta  (near  Moose  Pass,  British  Columbia),  at  7,000  feet 
altitude,  August  2,  1911,  by  N,  Hollister;  male  adult,  skin  and  skull, 
no.  1741G5,  U.  S.  Natl.  Mus.;  original  number,  3863. 

Range. — Northern  Rocky  Mountain  region  in  western  Alberta, 
eastern  British  Columbia,  nortliern  and  central  Idaho,  and  western 
Montana;  north  to  Mount  Selwyn,  British  Columbia;  south  to  Edna 
and  Ketclium,  Idaho;  west  to  the  Columbia  River  Valley,  southeast- 
ern British  Columbia  (fig.  20).  Zonal  range:  Canadian  and  Hud- 
soiiian. 

Extei'nal  characters. — Similar  to  G.  I.  cinerascens^  but  mantle 
darker  and  more  extensive,  reaching  over  the  shoulders  and  in  some 
specimens  nearly  to  the  middle  of  the  back ;  under  side  of  tail  averag- 
ing darker. 

Cranial  characters. — Skull  closely  similar  to  that  of  cinerascens; 
much  larger  than  that  of  0.  I.  castaiiurus. 


""  Kansas  Univ.  Mus. 


200  NORTH  AMERICAN  FAUNA  [No.  56 

Color. — Head,  neck,  and  shoulders  russet,  varying  to  mars  brown; 
median  dorsal  area  smoke  gray,  shaded  on  the  rump  with  dull  mars 
brown  or  Vandyke  brown,  this  color  nearly  solid  on  the  thighs;  eye 
ring  creamy  white;  light  dorsal  stripes  creamy  white,  shaded  with 
pale  pinkish  buff ;  inner  pair  of  black  stripes  nearly  as  wide  as  outer 
pair,  but  not  reaching  quite  so  far  back ;  sides  pinkish  buff  or  warm 
buff ;  under  parts  pinkish  buff ;  front  feet  pinkish  buff ;  hind  feet  pale 
pinkish  buff  or  buffy  white;  tail  above,  black,  bordered  with  cin- 
namon buff;  tail  beneath,  cinnamon  buff  or  pinkish  cinnamon,  with 
a  subterminal  band  of  black.  Winter  pelage  (Ptarmigan  Lake, 
Alberta,  July  9,  and  St.  Mary  Lake,  Mont.,  June  5)  :  Head,  neck,  and 
median  dorsal  area  smoke  gray ;  ears  russet,  edged  with  pinkish  buff ; 
sides,  under  parts,  and  feet  pale  pinkish  buff;  under  side  of  tail  pink- 
ish buff  or  cinnamon  buff. 

Variation. — While  the  topotype  series  is  quite  uniform  in  the  color 
of  the  under  surface  of  the  tail,  the  series  from  northwestern  Mon- 
tana shows  more  variation,  some  specimens  having  a  paler  tail  (about 
as  in  cinerascens)  and  others  a  slightly  darker  tail,  with  some  admix- 
ture of  black. 

Molt. — A  male  specimen  from  Canadian  National  Park,  Alberta, 
July  5,  shows  fresh  summer  pelage  on  the  shoulders  and  crown ;  two 
female  specimens  from  Teton  County,  Mont.,  June  14  and  19,  show 
new  pelage  in  irregular  patches  on  the  head  and  shoulders;  a  breed- 
ing female  from  Thompson  Falls,  Mont.,  July  27,  shows  fresh  pelage 
covering  the  head  and  ears,  the  rest  of  the  pelage  being  in  worn  con- 
dition. A  breeding  female  from  Canadian  National  Park,  Alberta, 
July  12,  shows  fresh  summer  pelage  covering  the  head  and  part  of  the 
shoulders ;  another  fem.ale  from  Rocky  River,  Alberta,  August  12,  had 
just  begun  to  molt,  the  new  summer  pelage  covering  only  the  head 
and  face. 

Measurements. — Average  of  16  adults  from  near  type  locality:  Total  length, 
292.5  (264-308)  ;  tail  vertebrae,  103.5  (94-112)  ;  hind  foot,  43.1  (40-46)  ;  ear 
from  notch,  13.5  (12-15).  Skull:  Average  of  10  adult  males  from  near  type 
locality:  Greatest  length,  44.1  (42.1-46.6);  palatilar  length,  20.6  (20-21.5); 
zygomatic  breadth,  27.4  (26.2-28.9)  ;  cranial  breadth,  19.9  (19.2-20.4)  ;  interor- 
bital  breadth,  10.7  (9.9-12)  ;  postorbital  constriction,  13.2  (12.5-14)  ;  length 
of  nasals,  15.5  (14.7-16.1)  ;  maxillary  tooth  row,  8.6  (8-9.1).  Average  of  7 
adult  females:  Greatest  length,  43.3  (42.3-44.6);  palatilar  length,  20.2  (20- 
20.5)  ;  zygomatic  breadth,  26.9  (26.1-27.3)  ;  cranial  breadth,  19.4  (19-19.6)  ; 
interorbital  breadth,  10.4  (10-10.7)  ;  postorbital  constriction,  12.7  (12.3-13)  ; 
length  of  nasals,  14.9  (14.3-15.9)  ;  maxillary  tooth  row,  8.4  (8.1-8.7). 

Weight. — ^A  female  from  Lost  River  Mountains,  Idaho,  weighed  12  ounces. 

Remarks. — This  wide-ranging  form  was  for  a  long  time  confused 
with  cinerascens  until  separated  by  Hollister  in  1911.  It  is  one  of 
the  largest  and  most  richly  colored  of  all  the  races.  It  undoubtedly 
intergrades  vv^ith  cinerascens,  but  there  is  no  material  available  to 
prove  such  intergradation.  It  is  not  strongly  differentiated  from 
cinerascens.,  but  may  be  distinguished  by  its  darker  and  more  exten- 
sive mantle  in  summer  pelage,  and  by  its  darker  tail. 

Specimens  examined. — Total  number,  279,  as  follows : 

Alberta:  Banff,  5;'''''  Burmis,  3;''  Canadian  National  Park,  5;''  Canmore,  3; 
Grand  Cache  River  (60-70  miles  north  of  Jasper  House),  4;  Hay  River 
(near   head),    1;    Henry  House    (15   miles    south),    9;   Jasper    House,   2; 

»>Nat.  Mus.  Canada. 
'^Amer.  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  201 

Jasper  Park,  17 ;  ^  Moose  Mountain,  3 ;  ^  Moose  Pass,  2 ;  Mountain  Park, 
2 ;  '^  Pobokton  River,  1 ;  Ptarmigan  Lake,  2 ;  ^  Laggan,  2 ;  Rocky  River 
(east  branch),  3;^'  Smoky  River  (head),  9;  Southesk  River,  2;^  Sulphur 
River,  2 ;  Waterton  Lake  Park,  11.'^ 

British  Coliimbia :  Barkerville,  11 ;  Glacier,  1 ;  ^  Golden  City,  1 ;  "  Green  Moun- 
tain (near  Rossland),  1  ;'^  Indian  Point  Lake,  S  ;*'  Indian  Point  Moun- 
tain, 2;^  Jarvis  Pass,  1;  Jubilee  Creek  (head,  near  Barkersville),  1 ;  ^^ 
Moose  Pass,  6;  Moose  River,  4;  Mount  Old  Glory  (near  Rossland),  5;*^ 
Mount  Selwyn,  8;  Parsnip  River  (head),  3;  Rossland,  1;^  Sukunka  River, 
5;  Trail,  2;^  Wapiti  River  (head),  1;  Yahk,  4;^  Yellowhead  Lake,  1; 
Yellowhead  Pass,  1. 

Idaho:  Birch  Creek  (mountains  west),  6;  Bitterroot  Mountains,  1;^^  Edna,  11; 
Elk  Summit  (Valley  County),  2;  Goldburg  (10  miles  west),  2;  Ketchum, 
6 ;  Lakeview,  2 ; ""  Lost  River  IMountains,  28  ;  Mullan,  16 ;  Patterson,  1 :  Red- 
fish  Lake,  2;  "Salmon  River  Mountains"  (=Lemhi  Mountains),  7;  Summit 
(at  Trail  Creek,  Blaine  County),  2;  Warren,  1;  Wood  River  (head,  Blaine 
County),  2. 

Montana:  Bass  Creek  (near  Stevensville),  1;  Bear  Creek  (Great  Northern 
R.  R.,  Flathead  County),  1;  Florence,  4:^^  "Horse  Plains"  (=Plains),  10; 
Lake  Como  (Ravalli  County),  1;  Lolo  Hot  Springs,  1;  Nyack  (Flathead 
County),  2;  Prospect  Creek  (near  Thompson  Falls),  3;  St.  Mary  Lake,  3; 
Summit  (Great  Northern  R.  R.,  Flathead  County),  1;  Thompson  Falls,  11; 
Thompson  Pass,  2. 

CITELLUS  LATERALIS  CASTANURUS  (Mekriam) 

Wasatoh  Mantled  Ground  Squirrel 

Manilas  castanunis  Merriam,  North  Amer.  Fauna  4 :  19,  Oct.  8,  1890. 
[SpcnuopJiilns]  castanurtis  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  2:  84, 

1901. 
Citellus  castanurus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6:  106,  1905. 
Callospermophilus  castanurus  Lyon  and  Osgood,  U.  S.  Natl.  Mus.  Bull.  62:  173, 

1909. 

Type. — Collected  at  Park  City,  Wasatch  Mountains,  Summit 
County,  Utah,  July  3, 1890,  by  Vernon  Bailey ;  female  adult,  skin  and 
skull,  no.  |-|tM)  U.  S.  Natl.  Mus.  (Biological  SurA^ey  collection) 
(orig.  no.  1383), 

Range. — Mountains  of  extreme  westei'n  W^yoming,  southeastern 
Idaho,  and  north-central  Utah;  north  to  the  Teton  Range,  Wyo. ; 
east  to  the  Gros  Ventre  and  Salt  River  Ranges,  Wyo.;  south  in  the 
Wasatch  Range  to  Wasatch  County,  Utah  (and  probably  farther); 
west  to  mountains  east  of  Inkom,  Idaho  (fig.  20).  Zonal  range: 
Canadian  and  Hudsonian. 

External  character,^. — Compared  with  C.  I.  lateralis:  Head  and 
mantle  darker;  black  dorsal  stripes  nuich  more  prominent,  the  inner 
pair  ahvays  present  and  e(|ual  in  breadth  to  outer  pair;  under  side  of 
tail  darker  (more  tawny).  Compared  witli  C.  I.  cinera^scc/u:  General 
tone  of  upper  parts  more  vinaceous  (less  grayish)  ;  sides  of  face  and 
neck  less  ochraceous;  tail  nmch  darker.  Similar  to  C.  I.  connectens 
and  0.  I.  trepidus,  but  sides  of  face  and  neck  darker  (more  broAvn- 
ish) ;  tail  darker  beneath. 

Cranial  characters. — Skull  similar  to  that  of  trepidus  but  averag- 
ing slightly  smaller,  and  relatively  narrower  across  z3'gomata;  de- 
cidedly smaller  than  that  of  cinerascens  or  of  lateralis. 

31  Nat.  Mus.  Canada. 

^  Am<.T.  Mus.  Nat.  Hist. 

"Mus.   Vort.   Zool. 

**  Piovincial  Mus.,  Victoria,   Biitish  Columbia. 

'^  Montana  Stale  College. 

^^  Carnegie  Mus. 


202  NORTH  AMERICAN  FAUNA  [No.  56 

Color. — Fresh  summer  pelage :  Head,  nape,  ears,  shoulders,  and 
sides  of  neck  mikado  brown,  shaded  with  cinnamon  and  bordered  on 
the  throat  with  cinnamon  buff;  median  dorsal  area  and  rump  fawn 
color,  sprinkled  with  grayish  white ;  light  dorsal  stripes  pinkish  buff ; 
sides  light  ochraceous  buff ;  fore  feet  and  legs  pinkish  buff  or  cinna- 
mon buff;  hind  legs  and  thighs  mikado  brown,  the  feet  pale  pinkish 
buff;  tail  above,  black,  bordered  with  cinnamon  buff;  tail  beneath, 
russet,  the  hairs  edged  with  cinnamon  buff  and  with  a  subterminal 
band  of  black ;  under  parts  pinkish  buff  or  buffy  white. 

Molt. — An  adult  female  from  Park  City,  Utah,  July  4,  was  ac- 
quiring fresh  pelage  on  the  head,  shoulders,  and  middle  of  the  back ; 
another  from  the  Salt  River  Mountains,  V/yo.,  August  21,  was  still 
carrying  old,  moderately  worn  pelage  over  most  of  the  body  except- 
ing the  head,  w^here  new  pelage  is  appearing. 

Measurements. — Average  of  8  adult  males  from  type  locality :  Total  length, 
272  (25&-293)  ;  tail  vertebrae,  97.1  (85-110)  ;  hind  foot,  41.5  (39-44).  Average 
of  10  adult  females  from  type  locality:  271  (256-280);  95.7  (91-101);  40.4 
(38.5-42)  ;  ear  from  notch  (dry),  15  (14-17).  Sk^iU:  Average  of  10  adult  males 
from  type  locality:  Greatest  length,  42.3  (40.2-44.2);  palatilar  length,  19.8 
(19-21)  ;  zygomatic  breadth,  26.3  (25.4-27.3)  ;  cranial  breadth,  39.4  (18.8-20.1)  ; 
interorbital  breadth,  9.7  (8.9-10.2)  ;  postorbital  constriction,  12.5  (11.8-13.1)  ; 
length  of  nasals,  14.6  (13.5-16)  ;  maxillary  tooth  row,  8.1  (7.3-8.7).  Average  of 
10  adult  females  from  type  locality :  Greatest  length,  41.9  (40.4-42.8)  ;  palatilar 
length,  19.5  (18.5-20)  ;  zygomatic  breadth,  25.8  (25.4-26.8)  ;  cranial  breadth, 
19.1  (18.5-19.8)  ;  interorbital  breadth,  9.8  (9-10.9)  ;  postorbital  constriction, 
12.7  (12.1-13.7)  ;  length  of  nasals,  14.5  (13.6-15.3)  ;  maxillary  tooth  row,  7.9 
(7.1-8.4). 

Remarks. — This  race  clearly  belongs  in  the  chrysodeirus  group, 
intergrading  with  subspecies  trejndus  in  southern  Idaho.  A  series 
of  11  specimens  from  Rabbit  Creek,  8  miles  northeast  of  Inkom,  are 
paler  than  typical  castanurus.,  although  their  tails  are  about  as 
dark;  one  specimen  from  the  Bannock  Range,  west  of  Swan  Lake, 
has  a  paler  tail  and  is  best  referred  to  trepidus.  G.  I.  castanurus  is 
widely  different  from  lateralis  and  although  their  ranges  nearly  meet 
in  northern  Utah,  no  evidence  of  intergradation  has  been  found.  It 
iiitergrades,  however,  with  C.  I.  caryi  in  the  Gros  Ventre  Range  and 
probably  with  cinet'ascens  at  the  northern  end  of  the  Teton  Range, 
Wyo.  An  immature  specimen  from  Moose  Creek,  in  that  range, 
differs  from  typical  castanurus  in  having  the  under  side  of  the  tail 
a  paler  shade  of  red,  perhaps  indicating  an  approach  to  cinerascens. 
Nine  specimens  from  near  the  head  of  Twin  Creek,  in  the  Gros  Ventre 
Range,  Wyo.,  taken  by  Arthur  B.  Fuller  and  W.  P.  Bole,  Jr.,  of  the 
Cleveland  Museum,  are  typical  castanurus.^  whereas  a  single  speci- 
men taken  by  H.  E.  Anthony,  12  miles  northwest  of  Kendall — and 
thus  in  practically  the  same  region — shows  approach  to  caryi  in  its 
paler  tail. 

Specimens  examined. — Total  number,  112,  as  follows : 

Idaho:  Big  Hole  Mountains,  1;  Crow  Creek  (Preuss  Mountains),  2;  Inkom  (8 

miles  northeast),  11. 
Utah:   Barclay    (Salt  Lake  County),  11;  Blacksmiths  Fork   (Cache  County), 

2;  Bear  Lake    (east  side),  4;  Logan  Canyon    (Cache  County),  3;"  Park 

City  (Summit  County),  47;  Sardine  Canyon   (Cache  County),  1." 
Wyoming:  Cokeville,  1;  Flat  Creek   (at  head,  Teton  County),  1;  Gros  Ventre 

Mountains    (head  of  Twin  Creek),   10;^^  Jackson,  5;   Kendall    (12  miles 


"  Utah  state  Agr.  College. 
«  Cleveland  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  203 

northwest,  Sublette  County),  1;  La  Barge  Creek  (9,000  feet  altitude),  2; 
Merna  (Sublette  County),  1;  Salt  River  Mountains,  4;  Smiths  Fork 
(head,  Lincoln  County),  3;  Stanley  (=MidclIe  Finey  Lake),  1;  Teton 
Mountains  (south  of  Moose  Creek),  1. 

CITELLUS   LATERALIS   CHRYSODEIRUS    (Mekriam) 

Golden-mantled  Gkound  Squirrel 

(PL  11) 

Tamias  chrysodcirus  Merriam,  North  Amer.  Fauna  4 :  10,  Oct.  8,  1890. 
Callospermophilus  chrysodcirus  Merriam,  North  Amer.  Fauna  16 :  90,  1899. 
iSpermophilus'\  chrysodcirus  Elliot,  Field  Columb.  Mus,  Pub.,  Zool.  Sor.  2:  84, 

1901. 
CitcUits  chrysodcirus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  3 :  288,  19(^)4. 

Type. — Collected  at  Fort  Klamath,  Oreg.,  July  31,  1888,  by  Samuel 
Parker;  male  adult,  skin  and  skull,  no.  186164,  U.  S.  Natl.  Mus.  (no. 
ff4t>  Merriam  collection)   (orig.  no.  143). 

Range. — Interior  Oregon  and  eastern  California  north  to  the  Co- 
lumbia River;  east  to  the  foothills  of  the  Blue  Mountains;  south  (in 
the  Sierra  Nevada)  to  Tulare  County,  Calif.;  west  to  and  including 
the  Cascades  in  Oregon,  and  Mount  Shasta,  Calif,  (fig.  20).  Zonal 
range:  Transition,  Canadian,  and  Hudsonian. 

External  characters. — Compared  with  C.  saturatus  and  C.  I.  later- 
alis: Head  darker;  mantle  more  extensive  and  brighter  colored; 
black  dorsal  stripes  broader  and  more  extensive,  the  inner  pair  equal 
in  width  to  outer  pair;  under  side  of  tail  darker  (more  tawny). 
Compared  with  C.  I.  castanurus:  Mantle  lighter  (more  yellowish); 
light  dorsal  stripes  clearer  white;  under  side  of  tail  paler;  external 
measurements  averaging  smaller. 

Cranial  characters. — Skull  similar  to  that  of  lateralis,  but  smaller, 
with  relatively  shorter  rostrum  and  nasals;  postorbital  constriction 
relatively  greater.  Compared  with  saturatus:  Much  smaller,  but  post- 
orbital  constriction  relatively  greater. 

Color. — Summer  pelage:  Top  of  head  mikado  brown;  sides  of  head 
and  neck,  ears,  and  shoulders  briglit  ochraceous  tawny;  sides  of  nose 
and  lower  cheeks  warm  buff;  median  dorsal  area  vinaceous  buff  or 
tilleul  IjufF,  shading  to  fawn  color  or  army  brown  on  the  rump;  light 
dorsal  stripes  creamy  white  or  sometimes  ochraceous  buff;  inner  pair 
of  black  strii)es  equal  in  length  and  breadth  to  outer  pair;  lower  sides 
and  feet  pinkish  buff;  tail  above,  black,  sprinkled  with  pinkish  buff 
or  ochraceous  buff;  tail  beneath,  tawny  or  ochraceous  tawny  bordered 
with  black  and  edged  with  pinkish  buff  or  ochraceous  buff;  under 
parts  pinkish  l)uff  or  buffy  white.  Winter  pelage  (October-April)  : 
General  tone  of  upper  parts  more  grayish;  mantle  poorly  defined; 
head  fawn  color  or  mikado  brown;  sides  of  head  and  neck  cinnamon 
buff;  median  dorsal  area  liglit  drab,  shading  to  fawn  color  on  the 
rump;  under  side  of  tail  clay  color;  feet  buffy  wdiite. 

Molt. — An  adult  male  from  Beech  Creek,  Oreg.,  July  2,  had  nearly 
(■om])leted  the  molt,  new  |)elage  covering  most  of  the  body  except  the 
hinder  back  and  hind  legs,  which  are  in  old,  worn  pelage.  An  adult 
female  from  Diamond  Lake,  Oreg.,  August  12,  and  another  from 
Mount  Shasta,  Calif.,  August  21,  had  just  begun  to  acquire  new 
pelage  on  the  head  and  the  middle  of  the  back. 


204  NORTH  AMERICAN  FAUNA  [No.  56 

Measurements. — Average  of  10  adult  males  from  Fort  Klamath  and  Crater 
Lake,  Oreg. :  Total  length,  259  (242-275)  ;  tail  vertebrae,  89.6  (83-94)  ;  hind  foot. 
39.7  (39^1)  ;  ear  from  notch  (dry),  15.2  (14-16).  Average  of  10  adult  females 
from  same  localities:  253.5  (235-278);  88.1  (82-102)  ;  39.1  (37^1)  ;  15.2  (14- 
16.5).  Skull:  Average  of  10  adult  males  from  same  localities:  Greatest  length, 
42.3  (41^4)  ;  palatilar  length,  19.5  (18.5-21)  ;  zygomatic  breadth,  26.3  (24.8-28)  ; 
cranial  breadth,  19.5  (19.1-20)  ;  interorbital  breadth,  10.2  (9.3-11.2)  ;  postorbital 
constriction,  13.2  (12.5-13.9)  ;  length  of  nasals,  14.4  (13.3-15.8)  ;  maxiUary  tooth 
row,  8.2  (7.6-8.6).  Average  of  10  adult  females  from  same  localities:  Greatest 
length,  41.1  (39.6-42.7)  ;  palatilar  length,  18.7  (18-19.5)  ;  zygomatic  breadth,  25.5 
(23.8-26.4)  ;  cranial  breadth,  19.3  (18.1-19.9)  ;  interorbital  breadth,  9.5  (9.1-10)  ; 
postorbital  constriction,  12.7  (11.2-14)  ;  length  of  nasals,  14.4  (13.2-15.4)  ;  max- 
illary tooth  row,  8  (7.4-8.7). 

Weight.— Average  of  10  males,  181  g  (155-218)  ;  of  10  females,  199  g  (136-245) 
(Grinnell  and  Dixon,  1918,  p.  676). 

Remarhs. — Over  its  very  wide  range,  this  subspecies  intergrades 
with  several  other  races.  Specimens  from  Four  Mile  Lake,  Oreg.,  a 
short  distance  southwest  of  Fort  Klamath,  have  darker  and  more  ex- 
tensive mantles  than  typical  specimens ;  in  Siskiyou  and  Trinity  Coun- 
ties, Calif.,  intergradation  with  the  subspecies  G.  I.  niitratus  takes 
place,  the  large  series  from  there  being  referred  to  the  latter  form. 
At  the  southern  end  of  the  Sierra  Nevada  (Sequoia  National  Park, 
Mount  Wliitney,  etc.)  the  animals  differ  from  typical  chin/so- 
deirus  in  having  slightly  darker  mantles,  thus  approaching  G.  I.  her- 
nardinus  in  color;  their  skulls  are  also  closely  similar  to  those  of 
'bernardinus^  being  longer  and  relatively  narrower  than  typical 
chrysodeirus ;  the  tails,  however,  are  fully  as  long  as  in  chrysodeh-^s. 
Some  individuals  from  Mount  Whitney,  Bishop  Creek,  and  head  of 
San  Joaquin  River  have  whitish  feet  and  bellies,  thus  showing  ap- 
proach to  G .  I.  trepidns.  Several  specimens  from  East  Fork  of 
Kaweali  River  have  very  dark  tails,  darker  even  than  those  of 
G.  I.  certus. 

jSpeci7ne7is  examined. — Total  number,  543,  as  follows : 

California:  Alta  Peak  (Kaweah  River,  Sequoia  National  Park),  4;  Aspen 
Meadow  (Tuolumne  County),  7;  Bald  Moiuitain  (8  miles  west,  Shasta 
County),  1;  Bartle  (McCloud  River),  5;  Bieber  (Lassen  County),  1;  Big 
Valley  Mountains,  11;  Bishop  Creek  (9,000-10,000  feet  altitude,  Inyo 
County),  4;  Bear  Creek  Valley  (west  of  Dana,  Shasta  County),  1;  Beswick 
(Siskiyou  County),  1;  Bullfrog  Lake  (Fresno  County),  6;^^  Buck's  Ranch 
(Plumas  County),  1;  Bunch  Grass  Spring  (Madeline  Plains),  2;  Carberry 
Ranch  (12  miles  west  of  Burney,  Shasta  County),  6;  Chaparral,  3;^  Cisco 
(Placer  County),  1;  Cottonwood  Lakes  (Inyo  County),  1;^  Crown  Valley 
(Middle  Fork,  Kings  River,  Fresno  County),  1 ;  *"  Cutts  Meadow  (near  Hunt- 
ington Lake,  Fresno  County ) ,  2 :  ^''  Dinkey  Creek  ( North  Fork,  Kings  River, 
Fresno  County),  1 ;  Donner,  20;  Eagle  Lake,  1 ;  Eureka  Mill  (Shasta  County), 
1 ;  Evolution  Lake  (head  South  Fork,  San  .Joaquin  River),  1 ;  *"  Foster  Ridge 
(near  Huntington  Lake,  Fresno  County),  1;*°  Goose  Lake,  2;  Goose  Nest 
Mountain  (Siskiyou  County),  6;  Greenville  (8  miles  northwest),  13;  Hay- 
den  Llill  (Lassen  County),  3;  Horse  Corral  Meadows  (north  of  Mount  Silli- 
man,  Fresno  Coimty),  4;  Hope  Valley  (Alpine  County),  1;  Huntington  Lake 
(Fresno  County),  1;"  Ice  Caves  (6  miles  southwest  of  Tule  Lake),  2; 
Kaweah  River  (East  Fork,  Sequoia  National  Park),  7;  Kearsarge  Pass 
(Fresno  County,  5;'*  Lassen  County,  6;  Lassen  Creek  (east  side  of  Goose 
Lake),  7;  Lassen  Peak,  15;  Letter  Box  (Plumas  County),  2;  Little  Onion 
Valley,  1;^°  Little  Pete  Meadow  (Kings  River,  Fresno  County),  1;**  Long 
Valley  (Mono  Comity),  1;^°  Madeline  Divide,  1;  Madeline  Plains,  1;  Marie 
Lake  (Selden  Pass,  Fresno  County),  1;^°  Markleeville  (Alpine  County),  2; 


s^Miis.  Vert.  Zool. 
^"Cleveland  Mus.  Nat.  Hist. 
*i  Wm.  T.  Shaw  collection. 
« Field  Mus.  Nat.  Hist. 


1938]  REVISION  OF  THE  GIIOUND  SQUIRRELS  205 

McCloud  (Siskiyou  County),  2;  McClure  Meadow  (head  South  Fork,  San 
Joaquin  River),  1;*"  McKinneys  (Lake  Tahoe),  2;  Merced  River  (near 
head),  1;  Merced  River  (Fish  Camp,  on  South  Fork),  1;  Mohawk  (Pluiuas 
County),  1;  Mono  Lake,  5;^"  Mono  Pass,  1;  Mount  Dana,  1;  Mount  Shasta, 
55 ;  Mount  Tallac,  5 ;  Mount  Unicorn,  1 ;  Mount  Whitney,  27 ;  Mulkey  Mead- 
ows (15  miles  south  of  Mount  Whitney),  5;  Onion  Valley  (Inyo  County), 
4;^*  Owens  River  (head),  2;  Petes  Valley  (Lassen  County),  1;  Picard 
(Siskiyou  County),  1 ;  Quincy,  1 ;  San  Joaquin  River  (near  head),  1 ;  Sequoia 
National  Park,  4;  Shingletown  (Shasta  County),  1;  Sierra  Valley  (Plumas 
County),  1;  Sisson  (Siskiyou  County),  1;  Summit  Meadow  (Tulare  County), 
1;  Susan  River  (Lassen  County),  1;  Susanville  (12  miles  west),  2; 
Tahoe  (Placer  County),  1;  Tenaya  Lake,  1;  Tuolumne  Meadows,  3;  Whit- 
ney Meadows  (10  miles  south  of  Mount  Whitney),  1. 

Nevada:  Glenbrook  (Lake  Tahoe),  6;  Lake  Tahoe,  2. 

Oregon:  Antelope  (Wasco  County),  2;  Arnold  Ice  Cave  (Deschutes  County), 
1;  Austin  (Grant  County),  1;  Beech  Creek  (Grant  County),  1;  Bend,  7; 
Chiloquin  (Klamath  County),  1;  Crater  Lake,  28;  Crooked  River  (20  miles 
southeast  of  Prineville),  1;  Diamond  Lake  (Douglas  County),  5;  Drew 
Creek  Valley  (Lake  County),  2;  Fort  Klamath,  74;  Four-mile  Lake  (Klam- 
ath County),  12;  Francisville  (Wheeler  County),  1 ;  Fremont  (Lake  County), 
4;  Friend  (Wasco  County),  2;  Gateway  (Jefferson  County),  2;  Goose  Lake 
Mountains,  1;  Hay  Creek  (12  miles  east,  Jefferson  County),  2;  Heppner,  1; 
Howard  (Crook  County),  3;  John  Day  River  (Crown  Rock),  3;  Kamela 
(Union  County),  1;  Lone  Rock  (Gilliam  County),  10;  Maupiu  (Wasco 
County),  2;  McKenzie  Bridge,  1;  Meacham  (Umatilla  County),  1;  Mill 
Creek  (20  miles  west  of  Warmsprings),  G;  Miller  (mouth  of  Deschutes 
River),  6;  Mount  Hood,  7;  Mount  Mazama  (Anna  Creek,  Crater  Lake  Na- 
tional Forest),  4;  Naylox  (Klamath  Lake),  3;  Ochoco  National  Forest 
(Crook  County),  2 ;  O'Leary  Mountain  (10  miles  south  of  McKenzie  Bridge), 
1;  Paulina  Lake,  4;  Rock  Creek  (Baker  County),  1;  Silver  Lake  (10  miles 
southwest),  2;  Sisters  (Deschutes  County),  4;  Strawl)erry  Mountains,  10; 
Three  Sisters,  5;  AVapinitia  (Wasco  County),  9;  Warm  Springs  River 
(mountains  north),  1;  Willows  (Gilliam  County),  1. 

CITELLUS    LATERALIS    CONNECTENS    (Howei.l) 
Blue  Mountains  Mantled  Gkound  Squibkei^ 

CallospermophiJuii  chrysodeirus  conncctcns  Howell,  Jour.  Mammal.  12 :  1(51, 
May  14,  1931. 

Type. — Collected  at  Hoinestead,  Oro^^.,  June  1,  1916,  by  H.  H. 
Sheldon;  male  adult,  skin  and  skull,  no.  212461,  U.  S.  Natl.  Mus. 
(Biological  Survey  collection^   (orig.  no.  535). 

Range. — The  Blue  Mountains  region  of  nortlieastern  Oregon  and 
southeastern  Washington  (fig.  20).  Zonal  range:  Transition  and 
Canadian. 

External  characters. — Similar  in  sunnner  pelage  to  C.  I.  chryso- 
deirus^ but  head  and  mantle  darker;  shoulders  and  fore  back  more 
vinaceous  (less  ochraceous) ;  under  side  of  tail  paler.  Similar  in 
color  to  C.  I.  castanurus  but  under  side  of  tail  paler;  sides  of  face 
and  neck  paler  (more  ochraceous). 

Cranial  characters. — Skull  closely  similar  to  that  of  chrysodeirus^ 
averaging  slightly  larger. 

Color. — Summer  pelage  (June  1)  :  Head,  ears,  shoulders,  and  sides 
of  neck  russet,  shaded  on  sides  of  neck  and  around  ears  with  ochra- 
ceous buff  and  ochraceous  tawny,  and  bordered  next  the  throat  with 
cinnamon  buff ;  nape  and  foreback,  between  shoulders,  cacao  brown ; 
median  dorsal  area  fawn  color,  shading  to  army  brow^n  on  rump  and 
thighs;  sides  of  body  and  feet  pinkish  buff;  light  dorsal  stripes 


aoMuH.  Vert.  Zoo). 
"Clevelaud  Mus.  Nat.  Hist. 


206  NORTH  AMERICAN  FAUNA  [No.  56 

creamy  white,  tinged  with  pinkish  buff;  tail  above,  black,  bordered 
with  cinnamon  buff;  tail  beneath,  cinnamon  or  tawny,  edged  with 
cinnamon  buff,  and  with  a  subterminal  band  of  black;  under  parts 
pale  pinkish  buff  or  buffy  white.  Winter  pelage  (May  8)  :  Mantle 
not  well  defined ;  top  of  head  pinkish  cinnamon ;  median  dorsal  area 
cinnamon  drab,  shading  to  fawn  color  on  rump  and  to  army  brown 
on  thighs ;  light  dorsal  stripes  clear  white,  reaching  to  the  ears ;  sides 
of  neck  washed  with  cinnamon  buff ;  sides  of  body  pale  pinkish  buff. 
Molt. — An  adult  female  from  Homestead,  Oreg.,  June  9,  and  an- 
other from  Paradise,  Oreg.,  June  10,  were  acquiring  fresh  pelage  on 
the  head  and  shoulders,  the  pelage  on  the  rest  of  the  body  being  con- 
siderably worn  and  faded. 

Measurements. — Average  of  7  adult  males  from  type  region :  Total  length, 
266  (257-280)  ;  tail  vertebrae,  92  (80-98)  ;  hind  foot,  41.7  (40-43)  ;  ear  from 
notch  (dry),  14.8  (14-16).  Average  of  9  adult  females  from  type  region:  Total 
length,  266  (255-280)  ;  tail  vertebrae,  91.5  (80-100)  ;  hind  foot,  40.9  (40-43)  ; 
ear  from  notch  (dry),  14.1  (13.5-15).  Skull:  Average  of  9  adult  males  from 
type  region;  Greatest  length,  42.7  (41.5-44.6)  ;  palatilar  length,  19.7  (19-20.5)  ; 
zygomatic  breadth,  26.5  (25.8-27.5)  ;  cranial  breadth,  19.4  (18.5-20.3)  ;  interor- 
bital  breadth,  9.6  (9-10.4)  ;  postorbital  constriction,  12.3  (11-12.8)  ;  length  of 
nasals,  14.9  (14-15.6)  ;  maxillary  tooth  row,  8.2  (7.2-8.8).  Average  of  8  adult 
females  from  type  region:  Greatest  length,  42.4  (41.6-43.1)  ;  palatilar  length, 
19.5  (19-20.5)  ;  zygomatic  breadth,  26.1  (24.6-27)  ;  cranial  breadth,  19.3  (18.8- 
19.9)  ;  interorbital  breadth,  9.4  (8.9-9.7)  ;  postorbital  constriction,  12.6  (11.6- 
13.4)  ;  length  of  nasals,  14.5  (13.9-15.3)  ;  maxillary  tooth  row,  8.5  (7.9-8.9). 

Bemarks. — This  subspecies  is  most  nearly  related  to  chrysodeirus, 
with  which  it  intergrades  in  the  foothill  region  of  the  Blue  Moun- 
tains. It  is  very  distinct  from  C.  I.  tescorum  of  central  Idaho,  and 
their  ranges  apparently  do  not  meet. 

Specimens  examined. — Total  number,  40,  as  follows : 

Oregon:  Anthony  (Baker  County),  1 ;  *^  Cornucopia  (Baker  County),  6 ;  *^  Home- 
stead (Baker  County),  7;  Joseph,  1;*'  Paradise  (15  miles  northeast,  Wal- 
lowa County),  1;  Troy  (Wallowa  County),  4;  Wallowa,  1;  Wallowa  Can- 
yon, 2 ;  Wallowa  Lake,  3. 

Washington:  Anatone  (Asotin  County),  2;  Dayton,  2;^°  Godman  Springs  (Co- 
lumbia County),  6;^^  Grand  Ronde  River  (6  miles  south  of  Anatone),  2; 
Humpeg  Falls  (Columbia  County),  2.*^^* 

CITELLUS    LATERALIS    TREPIDUS    (Taylor) 

Nevada  Mantled  Ground  Squirrel 

Callospermopliihis  trepidus  Taylor,  Calif.  Univ.  Pubs.,  Zool.  5:  283,  Feb.  12,  1910. 
Citellus  trepidus  Elliot,  Check-list  Mamm.  North  Amer.  Sup.,  p.  29,  1917. 
Callospermophilus  clrrysodeirus  perpallklus  Grinnell,  Calif.  Univ.  Pubs.,  Zool. 
17:  429,  1918  (White  Mountains,  Calif.). 

Type. — Collected  at  head  of  Big  Creek,  Pine  Forest  Mountains, 
Humboldt  County,  Nev.  (8,000  feet  altitude),  June  27,  1909,  by  W.  P. 
Taylor  and  C.  H.  Richardson,  Jr.;  male  adult,  skin  and  skull,  no. 
8240,  Mils.  Vert.  Zool.  (orig.  no.  768). 

Range. — Southeastern  Oregon,  southern  Idaho,  northern  and  cen- 
tral Nevada,  and  northwestern  Utah;  north  in  the  Snake  River  Val- 
ley to  southern  Baker  County,  Oreg.  (Home  P.  O.) ;  west  to  Mount 
Warner,  Oreg.,  and  the  Granite  Range,  Nev.;  south  to  the  Toyabe 
Mountains,  Nev.  and  the  AVhite  and  Inyo  Mountains,  Calif.;  east  to 
Bannock  County,  Idaho  (Swan  Lake)  and  the  Snake  Range,  eastern 


*^  S.  G.  Jewett  collection,  Portland,  Oreg. 
*^  Univ.  Michigan  Mus.  Zool. 
■"iMus.  Vert.  Zool. 
*'  Carnegie  Mus. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  207 

Nevada  (fig.  20).  Zonal  range:  Upper  Sonoran,  Transition,  and 
Canadian. 

External  chaTacters. — Similar  to  G.  I.  chrysodei7nis^  but  tail  longer 
and  coloration  paler;  upper  parts  more  grayish  (less  brownish),  es- 
pecially on  the  rump;  under  parts  and  feet  more  whitish  (less  buffy). 
Compared  with  C.  I.  castanuru^H :  Upper  parts  paler  (less  brownish) ; 
mantle  paler  (more  ochraceous) ;  tail  paler  beneath. 

Cranial  characters. — Skull  closely  similar  to  that  of  chrysodeirus ; 
interi^terygoid  fossa  and  nasals  averaging  slightly  narrower. 

Color. — Summer  felage  (June-July)  :  Top  of  head  hazel;  sides 
of  head  and  face,  and  shoulders,  ochraceous  tawny,  shaded  with 
cinnamon  buff;  ears  cinnamon  buff;  median  dorsal  area  vinaceous 
fawn,  more  or  less  shaded  with  grayish  white,  becoming  fawn  color 
or  army  brown  on  the  rump  and  thighs;  light  dorsal  stripes  creamy 
white  or  pinkish  buff;  both  pairs  of  black  stripes  of  equal  width, 
reaching  from  shoulders  to  hips;  lower  sides  pinkish  buff  or  pale 
pinkish  buff;  hind  feet  creamy  white  or  pale  pinkish  butt';  front 
feet  pinkish  butt';  tail  above,  black,  mixed  with  warm  buff  and  bor- 
dered with  the  same;  tail  beneath,  tavrny  or  cinnamon,  bordered 
with  black  and  edged  with  warm  buff;  under  parts  creamy  white, 
faintly  shaded  with  pale  pinkish  buff.  Winter  felage  (Ruby  Moun- 
tains, Nev.,  June  20)  :  Median  dorsal  area  nearly  uniform  pale  smoke 
gray,  shaded  with  vinaceous  cinnamon  on  nose  and  head;  mantle 
nearly  obsolete,  the  shoulders  and  sides  of  neck  washed  with  cin- 
namon butt'. 

Molt. — In  two  females  from  Wliite  Pine  County,  Nev.,  June  18  and 
23,  new  summer  pelage  is  coming  in  on  the  top  of  the  head. 

Measurementfi. — Average  of  10  adults  (4  males,  6  females)  from  type  locality: 
'I'otal  lensth,  208.6  (2r)2-28S)  ;  tail  vertebrae,  101.2  (90-108)  ;  hind  foot.  40.5 
(39-44);  ear  from  notch  (dry),  13.9  (13-10).  Skull:  AvcniKe  of  7  adults  (2 
males,  5  females)  from  type  locality:  Greatest  length,  42.8  (41.8-14)  :  palatilar 
length,  19.8  (19-20.2)  ;  zygomatic  breadth,  26.9  (25.6-27.7)  ;  cranial  breadth, 
19.8  (19.3-20.S)  ;  interorbital  breadth,  9.5  (9.1-9.8)  ;  postorbital  constriction, 
V2.2  (11.4-14)  ;  length  of  nasals,  14.9  (14.4-15.4)  ;  maxillary  tooth  row,  8.4  (8.1- 
9.3). 

Weight. — Average  of  10  males  from  White  Mountains,  Calif.,  182  g  (166.5- 
199.5)  ;  of  10  females,  160  g  (141-209.1)    (Grinnell  and  Dixon,  1918,  p.  682). 

Remarks. — This  race  is  only  slightly  different  from  typical 
chrysodeirus,  being  chiefly  distinguished  by  its  more  whitish  feet 
and  under  parts.  Occasional  specimens  from  within  the  range  of 
frepidus  are  difficult  to  distinguish  from  chrysodeirus. 

A  large  series  of  ^''perpallidus^^  (topotypes)  proves  on  comparison  to 
be  practically  identical  w^ith  trep/dic^. 

Specimens  examined. — Total  number,  260,  as  follows: 

California:  Glass  Mountain  (Mono  Hills,  Mono  County),  3;**  Inyo  Mountains, 
12;  Mammoth  (Mono  County),  1;^  Mammoth  Lakes,  1;'°  Sherwin  Hill, 
Round  Valley  (Mono  County),  4;-"*  White  Mountains,  02.™ 

Idaho:  Albion  (Cassia  County),  3;  Bannock  Mountains  (8  miles  west  of  Swan 
Lake),  1  ;  Silver  City,  10. 

Nevada:  Arc  Dome  (Toyabe  Mountains),  3;  Badger  (20  miles  northwest  of 
Summit  Lake,  Humboldt  County),  2;  Baker  Creek  (White  Pine  County), 
9;"  Bull  Run  Mountaiiis,  1;  Carlin,  1;^"  Cottonwood  Range,  3:  Edgewood 
(Douglas  County),   1;"  Granite   Creek,   5;    Lehman   Creek    (White   Pine 


4a  ripvel.Tnrt  I\[us.  Nat.  Hist. 

^8  Univ.  MidiiRan  Mus.  Zool. 

">  Forty  in  Mus.  Vevt.  Zool.  ;  six  in  Cleveland  Mus.  Nat.  TTist. 

"  Mus.  Vfirt.  Zool. 

'''  Amer.  Mus.  Nat.  Hist. 


208  NORTH  AMERICAN  FAUNA  [No.  56 

County),  1;^  Little  Owyhee  River,  9;  Monitor  Mountains  (25  miles  south- 
west of  Eureka),  6;  Mount  Siegel  (Douglas  County),  4;°"  Palisade,  1; 
Pine  Forest  Mountains,  37;^^  Reese  River  (head),  3;  Ruby  Mountains, 
5;  Ruby  Valley,  1;  Stella  Lake,  Snake  Mountains  (White  Pine  County), 
11;^'  Toyabe  Mountains,  4;  Virgin  Valley,  1;^  Willard  Creek  (White  Pine 
County),  5". 

Oregon:  Barren  Valley  (Steens  Mountain  region),  1;  Beulah,  1;  Buchanan 
(Harney  County),  7;  Burns,  2;  Cedar  Mountains, -3 ;  Cow  Creek  Lake,  1; 
Disaster  Peak  (Malheur  Comity),  1;  Drewsey  (Harney  County),  3; 
Harney  (Harney  County),  2;  Home  (Baker  County),  2;  Huntington,  5: 
McDermitt  Creek  (8  miles  northeast  of  McDermitt,  Nev.),  3;  Mount 
Warner  {—  Hart  Mountain,  Lake  County),  1;  Riverside  (Malheur  County), 
7;  Shirk  (6  miles  southeast  of  Blitzen,  Harney  County),  2;  Steens  Moun- 
tains, 2;  Westfall   (Malheur  County),  5. 

Utah:  Raft  River  Mountains  (17  miles  northwest  of  Kelton),  2.°* 

CITBLLUS  LATERALIS  CERTUS   (Goldman) 

Charleston  Mountains  Mantled  Ground  Squirrel 

Callospermopliilus  lateralis  certus  Goldman,  Jour.  Mammal.  2 :  232,  Nov.  29,  1921. 

Type. — Collected  at  north  base  of  Charleston  Peak,  Charleston 
Mountains,  Nev.,  June  29,  1915,  by  L.  J.  Goldman;  male  adult,  skin 
and  skull,  no.  208891,  U.  S.  Natl  Mus.  (Biological  Survey  collection) 
(orig.  no.  2270). 

Range. — Charleston  Mountains,  Nev.  (fig.  20),  Zonal  range: 
Transition. 

External  characters. — Similar  to  C .  I.  trepidus,  but  tail  shorter  and 
darker  beneath;  coloration  paler  and  more  grayish  (less  brownish)  ; 
black  dorsal  stripes  shorter,  the  inner  pair  narrower.  Compared 
with  0.  I.  chrysodeirus :  Coloration  much  paler  and  more  grayish; 
under  parts  and  feet  white  instead  of  buff;  tail  shorter  and  darker. 

Cranial  characters. — Skull  similar  to  that  of  trepidus,  but  averag- 
ing slightly  narrower  across  the  zygomata;  nasals  shorter,  and 
narrower  posteriorly. 

Color. — Sicmmer  pelage :  Head,  nape,  and  shoulders  mikado  brown, 
bordered  next  the  throat  with  warm  buff;  throat  warm  buff  in  some 
specimens;  middle  of  back  and  rump  smoke  gray,  mixed  with  cin- 
namon drab;  light  dorsal  stripes  white,  narrowing  posteriorly;  dark 
dorsal  stripes  reduced,  the  outer  pair  scarcely  reaching  the  hips, 
the  inner  pair  narrovrer  and  still  shorter;  hind  legs  washed  with 
mikado  brown;  hind  feet  creamy  white  or  pale  pinkish  buff;  front 
feet  pinkish  buff  or  pale  pinkish  buff;  tail  above,  black,  edged  with 
ochraceous  buff';  tail  beneath,  russet  or  tawny,  bordered  with  black 
and  edged  with  ochraceous  buff;  under  parts  creamy  white.  'Winter 
pelage:  Not  seen,  but  a  specimen  in  changing  pelage  (June  29)  in- 
dicates that  the  head  is  drab  gray  and  the  mantle  mostly  obsolete. 

Molt. — Specimens  taken  at  the  type  locality,  June  29  and  30  and 
July  2  are  in  process  of  molting ;  on  some,  the  heads  still  retain  some 
of  the  old  winter  pelage,  the  new  hair  coming  in  in  patches ;  a  male 
taken  July  6  has  the  entire  mantle  in  summer  pelage,  the  rest  of  the 
body  in  winter  pelage. 

Measurements. — Average  of  18  adults  (7  males,  11  females)  from  type 
locality:  Total  length,  249  (280-258)  :  tail  vertebrae,  77.4  (70-90)  ;  hind  foot, 
38.5  (35-41)  ;  ear  from  notch  (dry),  15.1  (14-16.5).  Skull:  Average  of  6  males 
(adult  and  subadult)  from  type  locality:  Greatest  length,  42.5  (41—43.4); 
palatilar  length,  19.9  (19-20.5)  ;  zygomatic  breadth,  26  (25-27.2)  ;  cranial 
breadth,  19.9   (19.3-20.3)  ;  interorbital  breadth,  9.8   (9.2-10.4)  ;  postorbital  con- 

^  Mus.  Vert.   Zool. 
^=Amer.  Mus.   Nat.   Hist. 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  209 

striction,  13.2  (12.S-13.8)  ;  length  of  nasals,  13.8  (13.3-14.2)  ;  maxillary  tooth 
row,  8.1  (7.8-8.6).  Average  of  7  adult  females;  Greatest  length,  41.7  (41-42.8)  ; 
palatilar  length,  19  (18-20)  ;  zygomatic  breadth,  25.2  (24.4-25.7)  ;  cranial 
breadth,  19.5  (19-20)  ;  interorbital  breadth,  9.4  (8.9-9.6),  postorbital  constric- 
tion, 12.9  (12.2-13.5)  ;  length  of  nasals,  13.7  (12.8-14.4)  ;  maxillary  tooth  row, 
8.3  (7.7-8.7). 

Remarks. — Isolated  on  the  Charleston  Mountains,  this  short-tailed 
pale  race  is  nearest  to  treindus  of  the  region  to  the  northward ;  al- 
though in  general  coloration  it  is  among  the  palest  of  the  races,  its 
tail  is  as  dark  as  in  any  of  the  subspecies. 

Specimens  examined. — Total  number,  21,°^  from  type  locality. 

CITELLUS  LATERALIS  BERNARDINUS  (MEauoAM) 
San  Bebnakdino  Mantled  Ground  Squirrel 

SpermopJiiliis  chrysodcirus  brevicaudns  Merriam,  Biol.  Soc.  Wash.  Proc.  8:  134, 

1893  (not  Bpermopliilus  hrcvicauda  Brandt,  1884). 
Spcrmophilus    (Callospennopliilus)    hcrnardinus    Merriam,    Science    (n.    s.)    8: 

782,  Dec.  2,  1898  (substitute  for  Irevicaudus) . 
Callospermophilus  hernardinus  Mearns,  U.  S.  Natl.  Mus.  Bull.  56:  313,  1907. 
Citellus  chrysodeirus  'hernardinus  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.  Ser.  6: 

107,  1905. 

Type. — Collected  on  San  Bernardino  Peak,  Calif.,  October  9,  1893, 
by  J.  E.  McLellan;  female  subadult,  skin  and  skull,  no.  56661,  U.  S. 
Natl,  Mus.  (Biological  Survey  collection)   (orig.  no.  274). 

Range. — San  Bernardino  Mountains  (6,700-11,485  feet,  fide  Grin- 
nell)  (fig.  20).    Zonal  range:  Canadian  and  Hudsonian. 

External  characters. — Closely  similar  in  summer  pelage  to  C.  I. 
clirysodevnis.,  but  mantle  averaging  slightly  darker,  especially  on  the 
nape;  in  winter  pelage  upper  parts  more  grayish  (less  vinaceous) ; 
under  parts  slightly  paler  (less  buffy)  ;  tail  shorter;  hind  foot  longer. 

Cranial  characters. — Skull  similar  to  that  of  chrysodeirus,  but 
averaging  slightly  larger,  with  longer  nasals. 

Color. — Summer  pelage:  Top  of  head  and  face  pecan  brown  or 
mikado  brown,  this  color  reaching  on  to  the  back  between  the  shoul- 
ders; sides  of  head  and  neck  ochraceous  tawny;  median  dorsal  area 
fawn  color  or  smoke  gray;  chin  and  throat  pale  pinkish  buflf;  belly 
creamy  white;  tail  beneath,  tawny.  Winter  pelage  (June)  :  General, 
tone  grayish  (decidedly  different  from  the  summer  pelage) ;  mantle 
only  faintly  indicated  and  much  paler;  top  of  head  and  face  cinna- 
mon; sides  of  head,  neck,  and  shoulders  ochraceous  buff;  dorsal  area 
smoke  gray,  shaded  with  cinnamon  drab;  sides  grayish  white;  feet 
grayish  white,  faintly  washed  with  pale  pinkish  buff;  tail  as  in 
summer. 

Molt. — A  male  taken  June  19  shows  fresh  summer  pelage  covering 
the  head  and  neck,  tlie  rest  of  the  body  being  in  worn  winter  pelage ; 
a  female  taken  June  28  shows  new  pelage  covering  the  nose  and  face, 
reaching  to  the  ears. 

Measurements. — Average  of  7  adult  males  from  San  Bernardino  Mountains : 
Total  length,  255  (240-205)  ;  tail  vertebrae,  77.3  (70-84)  ;  hind  foot,  42  (40- 
45)  ;  ear  from  notch  (dry),  15.4  (15-16).  Average  of  10  adult  females:  Total 
length,  249.5  (239-272)  ;  tail  vertebrae,  71.1  (03-80)  ;  hind  foot,  40.2  (.3&-42)  ; 
ear  from  notch,  15.6  (14-16.5).  Skull:  Average  of  9  adult  males:  Greatest 
length,  42.8  (41.8-43.7)  ;  palatilar  length,  19.5  (19-20)  ;  zygomatic  breadth,  26.0 
(26-27.8)  ;  cranial  breadth,  19.2   (18.7-19.5)  ;  interorbital  breadth,  10.7    (10.1- 


"  Seventeen  in  D.  R.  Dickey  collection. 
154970—38 14 


210  NORTH  AMERICAN  FAUNA  [No.  56 

11.6)  ;  postorbital  constriction,  12.9  (12.5-13.7)  ;  length  of  nasals,  15.7  (14.8- 
16.7);  maxillary  tooth  row,  8.3  (7.9-8.8).  Average  of  10  adnlt  females: 
Greatest  length,  42  (40.4-44)  ;  palatilar  length,  19.1  (18.5-20)  ;  zygomatic 
breadth,  25.8  (24.9-26.8)  ;  cranial  breadth,  19  (18.6-19.7)  ;  interorbital  breadth, 
10.2  (9.4-10.8)  ;  postorbital  constriction,  12.8  (11.9-13.7)  ;  length  of  nasals, 
15.4  (14.1-16.3)  ;  maxillary  tooth  row,  8.1   (7.5-8.5). 

Remarks. — Altliough  geographically  isolated  from  chrysodeirus^ 
this  race  is  so  close  to  the  latter  in  characters  that  a  subspecific  desig- 
nation seems  best  to  express  its  relationship.  As  pointed  out  under 
chrysodeirus,  specimens  of  that  race  from  the  southern  Sierra  Nevada 
approach  herna^rdinus  in  certain  characters. 

Specimens  examined. — Total  number,  49,  as  follows : 

California:    Big   Bear   Lake    (San   Bernardino   County),    1;    San   Bernardino 

Mountains,  48. 

CITELLUS  LATERALIS  MITRATUS  (Howell) 

YoixA  BoiXY  Mantled  Ground  Squirrel 

(Pis.,  27,  A;  32,  A) 

Callospermophihis  chrysodeirus  mitratus  Howell,  Jour.  Mammal.  12 :  161,  May  14, 
1931. 

Type. — Collected  on  South  Yolla  Bolly  Mountain,  Calif.,  July  30, 
1905,  by  J.  F.  Ferry;  male  adult,  skin  and  skull,  no.  138125,  U.  S. 
Natl.  Mus.  (Biological  Survey  collection)   (orig.  no.  13). 

Range. — Coast  ranges  of  northern  California,  from  Glenn  County 
north  to  southern  Siskiyou  County  (fig.  20).  Zonal  range:  Canadian 
and  Transition, 

External  characters. — Similar  to  C.  I.  chrysodeirus.,  but  upper 
parts  paler  and  more  grayish  (less  brownish),  especially  on  the 
rump ;  mantle  darker,  especially  on  sides  of  head  and  on  shoulders ; 
tail  averaging  longer  and  darker  beneath;  hind  feet  longer.  Com- 
pared with  C.  I.  trinitatis:  Upper  parts  much  paler;  mantle  deeper 
colored  and  more  extensive ;  external  measurements  smaller. 

Cranial  characters. — Skull  larger  than  that  of  chrysodeiriis.,  with 
longer  nasals.  Compared  with  trinitatis:  Skull  about  same  length, 
but  zygomata  more  widely  expanded  posteriorly  and  nasals  longer. 

Color. — Summer  pelage :  Head  and  mantle  russet,  this  color  extend- 
ing on  to  the  shoulders  and  fore  back,  shaded  on  sides  with  ochra- 
ceous  tawny ;  throat  and  sides  of  nose  Avarm  buff ;  ears  russet,  shaded 
with  ochraceous  tawny;  eye  ring  buffy  white;  median  dorsal  area 
smoke  gray,  shading  in  some  specimens  to  army  brown  on  rump  and 
thighs ;  light  dorsal  stripes  creamy  white ;  sides  of  body  pinkish  buff ; 
feet  cinnamon  buff;  tail  above,  black  or  fuscous  black,  mixed  with 
warm  buff;  tail  beneath,  taAvny,  bordered  with  fuscous  black  and 
edged  with  warm  buff;  under  parts  pinkish  buff,  shading  to  warm 
buff.  Winter  pelage  (September  26)  :  Head  sayal  brown  or  mikado 
brown ;  mantle  nearly  obsolete ;  sides  of  neck  clay  color,  washed  with 
dull  tawny;  otherwise  as  in  sununer. 

Molt. — Two  adult  females  from  Canyon  Creek,  Calif.,  taken  August 
21,  show  new  pelage  coming  in  on  the  head  and  the  middle  of  the 
back. 

Measurements.— ANQVBige  of  10  adults  (5  males,  5  females)  from  type  locality 
(including  2  from  Grindstone  Creek,  northern  Glenn  County)  :  Total  length, 
269  (254-283)  ;  tail  vertebrae,  94.1  (81-110)  ;  hind  foot,  41.4  (40-43)  ;  ear  from 
notch,  14.5   (13-10).     Skull:  Average  of  8  adults   (5  males,  3  females)   from 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  211 

same  localities:  Greatest  length,  43.5  (42^44.4)  ;  palatilar  lengtli,  20.3  (19.8- 
20.5)  ;  zygomatic  breadth,  27.5  (26.8-28.4)  ;  cranial  breadth,  19.9  (19.3-20.8)  ; 
interorbital  breadth,  10.1  (10-10.9)  ;  postorbital  constriction,  12.7  (12.4-13.2)  ; 
length  of  nasals,  15.7   (15.3-16.6)  ;  maxiUary  tooth  row,  8.1    (7.6-8.7). 

Remarks. — This  race  is  most  strongly  developed  in  the  vicinity  of 
South  Yolla  Bolly  Mountain.  The  specimens  from  northern  Trinity 
and  southern  Siskiyou  Counties  agree  in  size  with  typical  mitra- 
tus  but  are  slightly  darker;  the  skulls  average  a  little  longer,  and 
narrower  across  the  zygomata,  thus  showing  approach  to  trinitatis. 
Specimens  from  Bear  Creek  in  the  northeastern  corner  of  Trinity 
County  show  approach  to  chrysodeirus  in  small  average  size  of  the 
skulls. 

Specimens  examined. — Total  number,  83,  as  follows: 

California:  Bear  Creek  (head.  Trinity  County),  11;"  Canyon  Creek  (Trinity 
County),  4;  Castle  Lake  (Siskiyou  County),  2;^  Coast  Range  (17  miles 
west  of  Paskenta,  Tehama  County),  1;  Coffee  Creek  (North  Fork,  Trinity 
County),  3;"*  Grindstone  Creek  (Tehama  County),  2;  Grizzly  Creek  (head. 
Trinity  County),  5;"  Jackson  Lake  (Siskiyou  County),  5;"  Kangaroo  Creek 
(Siskiyou  County),  1;^  Rush  Creek  (head,  Siskiyou  County),  6;"  Salmon 
Mountains  (near  Etna  Mills),  11;  Salmon  River  (South  Fork,  Siskiyou 
Mountains),  8;"  Saloon  Creek  Divide  (Si.skiyou  County),  11;^*  South  Yolla 
Bolly  Mountain,  10;  Wildcat  Peak  (Siskiyou  County),  3.=' 

CITELLUS   LATERALIS   TRINITATIS    (Merriam) 

Trinity  Mountains  Mantleh)  Ground  Squirrel 

Callospermophiliis  chrysodeirus  trhiitutis  Merriam,  Biol.  Soc.  Wash.  Proc.  14: 

126,  July  19,  1901. 
Citellus  chrysodeirus  trinitatis  Elliot,  Field  Columb.  Mus.  Pub.,  Zool.   Ser.  6: 

107,  1905. 

Type. — Collected  at  5,700  feet  altitude  in  the  Trinity  Mountains, 
east  of  Hoopa  Valley,  Calif.,  September  10,  1898,  by  Vernon  Bailey; 
female  adult,  skin  and  skidl,  no.  95531,  U.  S.  Natl.  Mus.  (Biological 
Survey  collection)   (orig.  no.  6693). 

Range. — Trinity  Mountains  in  northern  Humboldt  County,  north 
through  the  Siskiyou  Mountains  to  southwestern  Oregon  (fig.  20). 
Zonal  range:  Canadian  and  Transition. 

Exteimal  characters. — Similar  to  G .  I.  chrysodeinis  but  darker  and 
more  brownish  above,  particularly  on  the  rump;  mantle  averaging 
slightly  darker;  sides  of  head  and  neck  darker;  tail  averaging  darker 
beneath;  external  measurements  greater. 

Cranial  characters. — Skull  similar  to  that  of  chrysodeirus  but  aver- 
aging longer  and  relatively  narrower,  the  zygomata  less  expanded 
posteriorly. 

Color. — Summer  pelage  (September  10)  :  Top  of  head  russet,  this 
color  reaching  over  the  crown  and  middle  of  tlie  nape,  and  on  sides 
of  head  from  the  eyes  to  the  shoulders,  bordered  next  the  throat  with 
cinnamon  buff  or  clay  color;  shoulders  more  or  less  shaded  with 
ochraceous  tawny;  ears  russet  to  ochraceous  tawny;  light  dorsal 
stripes  ochraceous  buff  on  the  shoulders,  creamy  wliite  for  the  rest 
of  their  length,  reaching  to  the  hips  but  not  on  to  the  rump;  median 
dorsal  area  fawn  color,  shading  to  natal  brown  on  rump  and  thighs; 
both  pairs  of  black  stripes  equal  in  width  and  nearly  equal  in  length 
to  white  stripes;  lower  sides  and  under  parts  pinkish  buff  or  warm 


"Mus.  Vert.  Zool. 


212        -         NORTH  AMERICAN  FAUNA  [No.  56 

buff;  feet  cinnamon  buff;  tail  above,  black  mixed  with  ochraceous 
tawny ;  tail  beneath,  tawny  or  bay  edged  with  black  and  ochraceous 
tawny. 

Measurements. — Average  of  6  adults  (3  males,  3  females)  from  type  locality: 
Total  length,  2S1.3  (26{>-295)  ;  tail  vertebrae,  90.7  (91-109)  ;  hind  foot,  43.2 
(41-44)  ;  ear  from  notch,  15.2  (14.5^16.5).  Skull:  Average  of  9  adults  (5  males, 
4  females)  from  type  locality  and  (3  females)  from  Siskiyou  Mountains :  Great- 
est length,  43.1  (41.2-44.8)  ;  paJatilar  length,  19.8  (19'-21)  ;  zygomatic  breadth, 
25.8  (24.8-27.5)  ;  cranial  breadth,  19.4  (19.1-19.9)  ;  interorbital  breadth,  9.9 
(8.8^11)  ;  postorbital  constriction,  12.9  (12.2-14.4)  ;  length  of  nasals,  14.9  (14.- 
15.8)  ;  maxillary  tooth  row,  8  (7.6-8.7). 

Remarks. — This,  the  darkest  race  of  the  chi^ysodeims  group,  occu- 
pies a  rather  limited  range  in  the  coast  mountains  of  northwestern 
California,  intergrading  with  C.  I.  iiiitratus  to  the  eastward. 

Specimens  examined. — Total  number,  30,  as  follows : 

California:  Preston  Peak,  3;  Siskiyou  Moimtains,  15;  Trinity  Mountains  (east 

of  Hoopa  Valley),  10. 
Oregon:  Briggs  Creek   (13  miles  southwest  of  Galice),  1;  Siskiyou,  1. 

CITELLUS  SATURATUS    (Rhoads) 

Cascade  Mantled  Ground  Squirrel 

Tamias  lateralis  satnratus  Rhoads,  Acad.  Nat.  Sci.  Phila.  Proc.  1895:  43,  April  9. 
[Spermophilus  lateralis]  satnratus  Elliot,  Field  Colunib.  Mus.  Pub.,  Zool.   Ser. 

2 :  83,  1901. 
Cltellus  lateralis  satnratus  Elliot,  Field  Culumb.  Mus.  Pub.,  Zool.  Ser.  6:  106, 

1905. 
C alios permophilus  lateralis  satnratus  Miller,  U.  S.  Natl.  Mus.  Bull.  79:  316,  1912. 

Type. — Collected  at  Lake  Kichelos  [=Keeclielus],  Kittitas  County, 
Wash.  (8,000  feet  altitude),  September  1893,  by  Allan  Rupert;  male 
adult,  skin  and  skull,  no.  8365,  Acad.  Nat.  Sci.  Phila.  (no.  1365,  Ehoads 
collection). 

Range. — The  Cascade  Mountain  region  of  western  Washington  and 
southern  British  Columbia;  north  to  Tulameen,  British  Columbia; 
south  to  the  Columbia  River  Valley,  southern  Washington;  east  to 
the  Similkameen  River,  British  Coliunbia  (fig.  20).  Zonal  range: 
Canadian. 

External  characters. — Size  largest  of  the  subgenus ;  coloration  very 
similar  to  that  of  C.  lateralis  loMralis.,  but  slightly  darker,  especially 
on  the  head,  rimip,  and  thighs ;  mantle  not  Avell  defined ;  under  parts 
more  buffy  (less  whitish) ;  median  pair  of  dark  stripes  obsolete  or 
much  reduced  and  outer  pair  reduced  in  length  and  obscurely  defined. 

Cranial  characters. — Skull  similar  to  that  of  lateralis  but  decidedly 
larger  in  all  measurements  except  the  nasals,  which  are  practically 
the  same  length.  Compared  with  G .  I.  chrysodeirus  and  G .  I.  tesco- 
rum:  Size  much  larger  with  longer  rostrum  and  nasals. 

Golor. — Fresh  summer  pelage:  Top  and  sides  of  head  russet  or 
mikado  brown,  bordered  next  the  throat  with  cinnamon  buff;  shoul- 
ders russet,  shaded  with  ochraceous  tawny;  ears  tawny,  shading  to 
pinkish  buff  on  posterior  margin;  eye  ring  pinkish  buff;  median 
dorsal  area  fawn  color  or  hair  brown;  hips  and  thighs  army  brown; 
light  dorsal  stripes  dull  buffy  white;  outer  pair  of  dark  stripes  black 
or  fuscous  black,  washed  with  tawny;  inner  pair  absent  or  faintly 
indicated;  sides  Avarm  buff;  front  feet  cinnamon  buff;  hind  feet 
pinkish  buff;  tail  above,  black,  mixed  with  cinnamon  buff;  tail  be- 


1938]  REVISION  OF  THE  GROUND  PQUIRRELS  213 

reath,  cinnamon  or  cinnamon  buff,  more  or  less  mixed  with  black; 
imder  parts  cinnamon  buff. 

Molt. — The  annual  molt  takes  place  in  June  or  July;  four  speci- 
mens from  Trout  Lake,  Wash.,  June  27  and  28,  show  fresh  pelage 
covering  the  head  and  shoulders,  the  remaining  parts  of  the  body 
being  in  a  worn  and  faded  pelage. 

Measurements. — Average  of  10  adult  males  from  the  Cascade  Moimtaius, 
Wash.:  Total  length,  305  (2S7-315)  ;  tail  vertebrae,  110.9  (100-118)  ;  hind  foot, 
46.5  (44-49)  ;  ear  from  notch  (dry),  17  (1&-18).  Average  of  10  adult  females 
from  same  localities:  Total  length,  300  (286-312);  tail  vertebrae,  106.5  (92- 
116);  hind  foot,  45.4  (43-48);  ear  from  notch  (dry),  17.8  (17-18.5).  Skull: 
Average  of  10  adult  males  from  the  Cascades :  Greatest  length,  46.4  (44-48.3)  ; 
palatilar  length.  21.4  (20-22.5)  ;  zygomatic  breadth,  28.9  (27.7-30.4)  ;  cranial 
breadth,  20.4  (19.5-20.9)  ;  interorbital  breadth,  11.5  (10.9-12.3)  ;  postorbital 
constriction,  13.4  (12.9-14.2)  ;  length  of  nasals,  16.8  (15.8-17.7)  ;  maxillary  tooth 
row,  8.9  (8.1-9.5)  ;  average  of  10  adult  females  from  same  localities:  Greatest 
length,  45.2  (43.9-46.3)  ;  palatilar  length,  20.8  (20-21.3)  ;  zygomatic  breadth, 
28.1  (27.2-28.6)  ;  cranial  breadth,  19.9  (19.5-20.2)  ;  interorbital  breadth,  11 
(10.6-11.6)  :  postorbital  constriction,  13.3  (12.4-14)  ;  length  of  nasals,  16  (15.6- 
16.6)  ;  maxillary  tooth  row,  9  (8.6-9.6). 

Remarks. — The  Cascade  mantled  ground  squirrel  differs  so  mark- 
edly from  the  other  members  of  the  subgenus  that  it  seems  necessary 
to  regard  it  as  a  full  species.  It  resembles  O.  lateralis  lateralis  of 
Colorado  more  nearly  than  any  of  the  other  races,  but  is  widely 
separated  from  it  geographically.  It  is  very  different  from  chryso- 
deirus.,  whose  range  it  nearly  meets  but  from  which  it  is  separated 
by  the  Columbia  River.  So  far  as  known,  there  is  a  wide  gap  in 
British  Columbia  between  the  range  of  saturatus  and  that  of  tes- 
cor^im  and  the  two  forms  are  very  dissimilar  in  their  characters. 

Specimens  examined. — Total  number,  111,  as  follows: 

British  Columbia:  Hedley,  5;"  Hope-Princeton  Summit,  3;"  Keremeos  (Ash- 
nola  Creek),  2;^^  Lightning  Lakes  (near  Boundary  Momunent  77,  Yale 
District),  1;  Second  Summit  (west  of  Skagit  River),  5;"  Skagit  River, 
1;'°  Tulameen,  1;^  Whipsaw  Creek    (branch   of   Similkameon   River),   1." 

Washington:  Bald  Mountain  (Okanogan  County),  1;  Barron  (Whatcom  Coun- 
ty), 5;  Bauerman  Ridge  (Okanogan  County),  1;  Bmnping  Lake  (Yakima 
County),  1;  Cleveland  (Klickitat  County),  1;  Easton,  18;  (JoUleiulalo,  4; 
Hannegan  Pass  (Wliatcom  County),  1;  Hart  Lake  (Chelan  County),  1; 
Keechelus  (Kittitas  County),  3;  Keechelus  Lake,  1;  Lake  Cli(>lan,  1;  Ma- 
zama  (Okanogan  County),  1;  Mount  Adams,  2;  Mount  Aix,  1;  Mount 
Rainier,  10:  Mount  St.  Helens,  3;  Rainier  Fork  Ridge,  4;  Spray  Park 
(Pierce  County),  1;"  Stehekin  (head  of  Lake  Chelan),  2;  "Tannum  River" 
(=Bumping  River),  1:  Trout  Lake  (Klickitat  County),  13;  Wenatcbce,  3; 
Wenatchee  i[jake,  1;  Whipsaw  Creek  (branch  of  Similkameen  River),  1  ;'^'' 
Yakima  Indian  Reservation  (Signal  Peak),  5. 

CITELLUS  MADRENSIS  (Mbrriam) 

SiFRRA  Madre  Ma  nixed  Ground  Squirket, 

(Pis.  27,  B;  Z2,  B) 

Callnspermophiltis  madrensis  Merriam,  Wash.  Acad.  Sci.  Proc.  3 :  563,  Nov.  29, 

1901. 
[Citrllus]   madrensis  Elliot,  Field  Columb.  Mus.  I'ub.,  Zool.  Ser.  4:  147,  1904. 

Type. — Collected  in  the  Sierra  Madre,  near  Guadalupe  y  Calvo, 
Chiiiuahua,  Mexico  (7,000  feet  altitude),  August  27,  1898,  by  E.  W. 


'•''  Natl.  Mus.  Canada. 

B»  Provincial  Mu.s.,  Victoria,  British  Columbia. 

*^  Univ.  IMicliiKiUi  Mu.s.  /ool. 


214  NORTH  AMERICAN  FAUNA  [No.  56 

Nelson  and  E.  A.  Goldman;  female  adult,  skin  and  skull,  no.  95363, 
U.  S.  Natl.  Mus.  (Biological  Survey  collection)   (orig.  no.  12923), 

Range. — Sierre  Madre,  Mexico,  from  northwestern  Durango  north 
to  latitude  27°,  west  of  Batopilas,  Chihuahua;  limits  of  range  not 
known  (fig.  20).     Zonal  range:  Transition. 

External  characters. — Similar  to  C .  lateralis  lateralis  and  G.  I. 
arizonensis.,  but  smaller,  with  much  shorter  tail ;  colors  much  duller, 
with  scarcely  any  trace  of  a  mantle;  black  stripes  short  and  poorly 
defined,  tending  to  become  obsolete ;  white  stripes  reaching  nearly  to 
the  root  of  the  tail. 

Cranial  characters. — Skull  similar  to  that  of  lateralis  but  smaller 
and  relatively  narrower;  zygomata  more  appressed;  brain  case  nar- 
rower and  more  highly  arched. 

Color. — Worn  simimer  pelage  (August  26-September  3) ;  Head 
and  face  hazel  or  sayal  brown;  eye  ring  buffy  white;  lower  cheeks, 
sides  of  lips,  and  fore  legs  warm  buff ;  sides  of  neck  and  shoulders 
rather  faintly  washed  with  cinnamon  buff  and  ochraceous  tawny; 
ears  thinly  clothed  on  outer  surface  with  cinnamon  hairs;  general 
tone  of  upper  parts  cinnamon  drab  or  fawn  color,  darkest  and  purest 
on  rump  and  thighs;  light  dorsal  stripes  dull  whitish  or  pinkish 
buff;  dark  stripes  blackish,  often  very  faintly  indicated;  sides  of 
body  cinnamon  buff  or  buffy  white ;  tail  above,  fuscous  black,  mixed 
with  warm  buff ;  tail  beneath,  warm  buff,  tipped  with  blackish ;  hind 
feet  pinkish  buff;  under  parts  pinkish  buff  or  buffy  white. 

Measurements. — Average  of  10  adults  (3  males,  7  females)  from  type  local- 
ity: Total  length,  227.8  (215-243)  ;  tail  vertebrae,  58.8  (52-66)  ;  hind  foot,  38.7 
(37-40)  ;  ear  from  notch  (dry),  16.4  (15-18).  ^kull:  Average  of  7  adults  (2 
males,  5  females)  :  Greatest  length,  42.3  (41.1-44.1)  ;  palatilar  length,  20.1 
(19.5-20.5)  ;  zygomatic  breadth,  25.6  (24.8-26.5)  ;  cranial  breadth,  18.9  (18.5- 
19.3)  ;  interorbital  breadth,  10.2  (9.9-10.5)  ;  postorbital  constriction,  12.3  (11.9- 
12.7)  ;  length  of  nasals,  15.8  (15.1-17)  ;  maxillary  tooth  row,  8.5   (8.3-8.7). 

Remarhs. — The  Sierra  Madre  ground  squirrel,  although  clearly 
derived  from  the  C.  I.  lateralis  stock,  has  become  so  strongly  differ- 
entiated that  it  must  be  treated  as  a  distinct  species.  The  known 
range  of  tnadrensis  is  separated  from  that  of  arizonensis  by  a  gap  of 
about  500  miles,  though  further  collecting  in  the  Sierra  Madre  may 
somewhat  extend  the  range  of  the  present  form  northward. 

E.  W.  Nelson,  who  discovered  the  species,  writes  of  its  habits  at 
the  type  locality  as  follows : 

Very  abundant  in  the  pine  woods  about  the  base  of  Mohinora  and  reaches 
the  extreme  summit  of  the  moimtains.  We  saw  them  all  along  our  route  from 
above  Guanacevi  In  Durango  to  Guadalupe  y  Calvo.  Their  range  extends 
only  a  little  below  7,000  feet  and  does  not  enter  the  pinyou  belt. 

Specimens  examined. — Total  number,  21,  from  type  locality. 

FOSSIL  SPECIES 

Eight  fossil  forms  in  the  genus  Citellus  have  been  described  from 
North  America.  Of  these,  two  are  from  Miocene  formations,  two 
from  the  Pliocene,  and  four  from  the  Pleistocene. 

The  most  primitive  species  at  present  known  is  Citellus  {Protosper- 
mophilus)   quatalensis  Gazin  (1930,  p.  64),  from  Quatal  Canyon,  8 


1938]  REVISION  OF  THE  GROUND  SQUIRRELS  215 

miles  east  of  Cuyama  Valley,  Calif.    Of  this  Miocene  form  the  de- 
scriber  says : 

On  the  basis  of  available  material,  Citellus  (Protospcnuophilus)  quatalcnsis 
appears  to  resemble  the  Recent  genus  or  subgenus  OtospermopMlus  more  nearly 
than  it  does  any  of  the  other  sciurids.  Moreover,  the  new  form  presents  an 
association  of  primitive  characters  which  suggests  that  the  dentition  possessed 
by  the  modern  otospermophilids  is  more  primitive  than  that  exhibited  by  the 
typical  citellids.  This  is  also  indicated  by  the  development  of  the  premolars, 
which  in  the  case  of  typical  CiteUiis  appear  to  have  taken  on  more  completely 
the  characters  of  the  molar  teeth.  From  this  consideration  it  seems  probable 
that  species  of  Citellus  may  have  been  derived  from  an  Otospermophilus-like 
ancestor,  probably  later  than  the  stage  represented  by  C.  (P.)  quatalensis, 
assuming  this  form  to  be  in  or  near  the  line  of  descent  of  the  ground  squirrels. 

Citellus  7'idgirayi  Gazin  (1932,  p.  61),  from  the  Skiill  Spring 
Miocene  beds,  Malheur  County,  Oreg.,  is  about  the  size  of  Citellus 
{Callosper?nophilus)  chrysodeirus  and  resembles  that  species  perhaps 
as  nearly  as  it  does  any  living  form.  It,  shows  conspicuous  differ- 
ences, however,  and  cannot  with  certainty  be  assigned  to  any  of  the 
modern  subgenera.  Compared  with  CaUosiyermophilus  the  skull  of 
C.  ridgwayi  is  flatter  on  the  superior  surface  and  wider  between  the 
orbits.  "The  outer  and  anterior  margin  of  the  zygoma  .  .  .  con- 
tinues forward  on  the  side  of  the  muzzle  as  a  small  ridge,  following 
the  contour  of  the  incisor  to  the  alveolus"  (Gazin).  The  molars  are 
low-crowned,  as  in  CallospermopMlus ;  ;;»*,  7;i\  and  w-  are  broader 
than  long,  and  differ  from  the  teeth  of  CallospermopMlus  in  having 
a  much  less  prominent  i^arastyle.  On  m  ^  and  m  -  the  protoloph  and 
metaloph  are  not  parallel  as  in  C alios permophiluJi^  but  converge 
toward  the  inner  side  as  they  join  the  protocone.  ]\P  has  a  reduced 
parastyle,  a  prominent  protoloph,  and  a  slight  ridge  in  the  basin  of 
the  tooth  running  toward  the  metacone. 

OtospermopMlus  gidleyl  Morriam,  Stock,  and  INIoody  (1925,  p.  68), 
from  the  Kattlcsnake  Pliocene,  John  Day  Valley,  Oreg.,  is  thus  char- 
acterized by  the  descri))prs: 

It  is  clearly  distinguished  from  the  other  sciurids  by  the  combined  char- 
acters of  the  relatively  shorter  anteroposterior  extent  of  all  the  cheek 
teeth.  ...  A  charnctcr  which  seems  to  distinguish  the  fossil  distinctly  from 
the  living  species  of  the  citellid  group  is  the  much  greater  relative  depth  aud 
apparently  shorter  proportions  of  the  lower  jaw. 

Citellus  hensoni  Gidley  (1922,  p.  122),  from  the  San  Pedro  Valley, 
Ariz.  (Pliocene),  was  described  from  the  molars  only;  as  stated  by 
Gidley,  these  teeth  seem  most  nearly  like  those  of  OtospermopMlus ; 
the  u])per  molars  are  relatively  narrow  in  the  transverse  diameter, 
and  the  posterior  loph  is  "broken  up  into  two  distinct  but  slightly 
joined  cuspules,  the  inner  one  of  which  is  a  rounded  cone  entirely 
disconnected  from  the  protocone." 

Citellus  tuitus  Hay  (1921,  p.  627),  from  Val  Verde  Mine,  Ariz. 
(Pleistocene),  Avas  compared  by  the  describer  with  C,  franJdinii,  but 
it  seems  to  be  nearer  to  C.  mexicanus ;  the  tooth  rows  converge  pos- 
teriorly about  as  in  that  species;  the  molars  are  higher-crowned  on 
the  inner  side;  mi'  is  longer  llian  broad  (nearly  quadrate  in  mexi- 
ca.'ims).  Except  for  the  more  hypsodont  molars,  (his  species  might 
be  referred  to  the  subgenus  Ictidomys. 

Citellus  coeMj<ei  Gidley  (1922,  p.  121),  from  the  San  Pedro  Valley, 
Ariz.  (Pleistocene),  was  based  on  a  right  maxillary  wnth  all  the 
molars,  and  part  of  a  lower  jaAv.     Both  this  species  and  C.  tuitus 


216  NORTH  AMERICAN  FAUNA  [No.  56 

seem  to  be  more  closely  related  to  C .  mexicamus  than  to  any  other 
living  species ;  both  differ  from  mexicanus  in  having  somewhat  stouter 
and  broader  molars.  The  present  species  may  with  little  hesitation 
be  referred  to  the  subgenus  Ictidomys.  Compared  with  tuitus,  it 
differs  in  having  the  protocone  of  the  upper  molars  stouter  and  less 
hypsodont;  the  metaloph  on  m^  and  m-  is  separated  from  the  pro- 
tocone by  a  wide  sulcus;  on  m^  the  protoloph  is  likewise  separated 
from  the  protocone  by  a  wide  sulcus ;  m^  and  m^  are  somewhat  heavier 
than  in  tuitus  but  m^  is  relatively  shorter. 

Citellus  taylori  Hay  (1921,  p.  616),  based  on  a  lower  jaw  from 
Pleistocene  deposits  near  San  Diego,  Tex.,  is  described  as  follows : 

The  jaw  and  teeth  seem  to  resemble  most  those  of  Citellus  toivnsendi  i=^wash- 
ingtoni].  .  .  .  The  molar  teeth  have  the  same  short,  broad  form,  and  the  jaw 
itself  is  hardly  different.  The  anterior  crest  of  each  tooth  is,  however,  not  so 
high  as  in  that  species  and  not  so  abruptly  steep  on  its  hinder  face.  .  .  . 
The  premolar  as  long  as  wide ;  the  cusps  of  its  anterior  crest  with  a  shallow 
notch  between  them. 

Citellus  heecheyi  captus  Kellogg  (1912,  p.  164)  from  Pleistocene 
deposits  at  Rancho  La  Brea,  Calif.,  is  characterized  by  the  describer 
as  follows: 

In  the  skull  the  width  between  the  premaxillae  and  the  anterior  width  of 
palate  are  less  than  in  Citellus  b.  fisheri.  The  bullae  are  relatively  long  and 
narrow.  In  the  lower  jaw,  the  tooth  row  is  long  and  the  teeth  heavy  in  pro- 
portion to  the  size  of  the  ramus ;  the  coronoid  process,  angle,  and  condyle  are 
small. 

This  form  is  considered  by  Dice  (1925,  p.  125)  to  be  referable  to 
O.  beecheyi  fisheri. 

In  addition  to  the  above  species,  several  of  the  modern  species 
have  been  found  in  Pleistocene  deposits,  as  follows : 

Citellus  tridecetnlineatus  has  been  recorded  from  the  Conard 
Fissure,  Newton  County,  Ark.  (Brown,  1908,  p.  194) ;  C.  douglasii 
and  C.  {CalJospermoj^hilus)  chinjsodeirus  have  been  found  in  cave 
deposits  in  Shasta  County,  Calif.  (Kellogg,  L.,  1912,  p.  155). 


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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  221 

HisAW,  Fkedeeick  L.,  and  Emeby,  Fuedeeick  E. 

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1928.  descriptions  of  six  new  north  American  ground  squireels.     Biol. 

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1931.   PREI.IMINARY     DESCRIPTIONS     OF     FOUR     NEW     NORTH     AMERICAN     GROUND 

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222  NORTH  AMERICAN  FAUNA  [No.  5G 

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1933.    THE    SE:XUAL    cycle    of    the    THIRTEEN-LINED    ground    squirrel    in    THE 

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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  223 

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1938]  REVISION  OF  THE  GROUND  SQUIRRELS  225 

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Mammal.  6:  157-162,  illus. 

19251.   OBSERVATIONS   ON   THE   HIBERNATION    OF  GROUND    SQUIRRELS.      JOUr.   Agr. 

Research  31 :  761-769,  illus. 

1926a.    A   SHORT  8E.\S0N   AND  ITS  EFFECT  UPON   THE  PREPARATION   FOR   REPRODUC- 
TION    BY    THE    COLUMBIAN    GROUND    SQUIRREL.        ECOlOgy    7  :    136-139, 

illus. 

1926b.    AGE  OF  THE  ANIMAL  AND  SLOPE  OF  THE  GROUND  SURFACE.  FACTORS   MODI- 
FYING  THE    STRUCTURE   OF    HIBERNATION    DENS    OF   GROUND    SQUIRRELS. 

Jour.  Mammal.  7 :  91-96,  illus. 

1926c.    THE  STORING  HABITS  OF  THE  COLUMBIAN  GROUND   SQUIRREL.      Anier.   Nat. 

60:  367-373. 
Slack,  J.  H. 

1861.    DESCRIPTION    OF   A   NEW    SPECIES   OF  RODENT  OF   THE  GENUS   SPERMOPHILUS. 

Acad.  Nat.  Sci.  Phila.  Proc.  1861 :  314. 
Sleogs,  Geokgb  Frederick. 

1026.  the  adult  anatomy  and  histology  of  the  anal  glands  of  the  rich- 
ardson ground  squirrel,  citkllus  richardsonii  sabine.    auat.  rec. 
32:  1-43. 
Stephens,  Frank. 

1906.  CALIFORNIA  MAMMALS.    351  pp.,  iUus.     Sau  Diego. 
Stonex  Witmek. 

1908.  THE  MAAfMALS  OF  NEW  JERSEY.     N.  J.  State  Mus.  Auu.  Rept.  1907,  211 
pp.,  illus. 
Storer,  Tracy  Irwin. 

1029.    SXTMMER   and    autumn    breeding    OF   the    CATJFORNIA    GROUND    SQIHRREX, 

Jour.  Manuunl.  10:  2.3.")-23(!. 


226  NORTH  AMERICAN  FAUNA  [No.  56 

Strong,  Richabd  Peabson. 

1923.  kesearch  in  some  aspects  of  disease  associated  with  the  fields  of 

GEiOLOGY,     ENTOMOLOGY,     AND     PAKAsiTOLOGY.    Science     (n.    s. )     57: 
507-520. 

SUBBEB,    THADDEUS. 

1932.  THE  MAMMALS  OF  MINNESOTA.     84  pp.  illus.   St.  Paul.      (Bull.  Minn. 

Dept.  Conserv.,  Div.  of  Game  and  Fish). 

SVIHLA,  AbTHTJB. 

1931.  oallospebmophilus  climbing  tbees.    Murrelet  12 :  80'. 

1933.  OCCUBBENCEI  OF   A   COLONY   OF   ALBINO    GBOUND   SQUIRREILS    NEAR   PULLMAN, 

WASHINGTON.     Murrclct  14 :  78. 

SWABTH,   HaBEY   SCHEXWALD. 

1929.    THE  FAXJNAL   AREIAS  OF   SOUTHERN    ABIZONA  :    A    STUDY   IN    ANIMAL  DISTRI- 
BUTION.    Calif.  Acad.  Sci.  Proc.   (4)   18 :  267-383,  illus. 
Taylob,  Walter  Penn. 

1910.  TWO  NEW  RODENTS  FROM  NEivADA.    Calif.  Univ.  Pubs.,  Zool,  5 :  283-302, 

illus. 

1911.  MAMMALS  OF  THE  ALEXANDER  NEVADA  EXPEDITION  OF    1909.      Calif.   UniV. 

Pubs.,  Zool.  7 :  205-307. 

1916.   A  NEW   SPERMOPHILE  FROM  THE  SAN   JOAQUIN  VALLEY,   CALIFORNIA,  WITH 
NOTES      ON      AMMOSPEEMOPHILUS      NELSONI      MEBRIAM.         Calif.      UniV. 

Pubs.,  Zool.  17:  15-20,  illus. 
Thomas,  Oldfiesld. 

1915.    THE  PENIS-BONE,   OR   "BACULUM",    AS   A   GUIDE  TO   THE  CLASSIFICATION    OP 

CERTAIN   SQUIRRELS.     Ann.  and  Mag.  Nat.  Hist.    (8)    15:383-387. 

1927.    A    SELECTION    OF   LEICTOTTPES    OF   AMERICAN    BODENTS    IN    THE   COLLEiCTION 

OF  THE  BBiTisH  MUSEUM.    Ann.  and  Mag.  Nat.  Hist.  (9)  19:  545-554. 
Town  SEND,  John  Kirk. 

1839.    NARRATIVE  OF  A   JOURNEY  ACROSS   THE  ROCKY   MOUNTAINS   TO  THE  COLUM- 
BIA BIVEB,  AND  A  VISIT  TO  THE  SANDWICH  ISLANDS,   CHILI,   &C.    WITH   A 

sciENTTFic  APPENDIX.     352  pp.     Philadelphia. 
Wade,  Otis. 

1927.  breeding  habits   and  eably   life   of   the  thirteen-striped  ground 

SQUIRREL,    CITELLUS   TBIDECEMUNEATUS     (MITCHILL) .       JOUT.    Mammal. 

8:  269^276. 

1980.    THE   BEHAVIOR    OF    CERTAIN    SPEBMOPHILES    WITH    SPECIAL   EEFEBENCE    TO 

AESTIVATION  AND  HiBEatNATiON.     Jour.  Mammal.  11 :  160-188. 
Ward,  Henry  L. 

1891.   DESCRIPTION  OF  TWO  NEW  SPECIES  OF  BODENTS  FBOM  MEXICO.      Amer.  Nat. 

25:  158-161. 
Warren,  Edward  Royal. 

1910.  THE  MAMMALS  OF  COLORADO.    300  pp.,  illus.     New  York. 

1924.  GROUND  SQUIRRELS  AND  WEASELS.    JouT.  Mammal.  5 :  265. 
Wood,  Frank  Elmer. 

1910.  a  study  of  the  mammals  of  champaign  county,  illinois.    111.  state 
Lab.  Nat.  Hist.  Bull.  8 :  501-613,  illus. 


Plate  14 

(Natural  size) 

A.  Citellus  (CaUospermophilus)  saturatus. 

B.  Citellus   {Poliocitelliis)   franklinii. 

C.  Citellus   (Ictidomys)    tridecemlineatus. 

D.  Citellus   (Xerospennophilus)   mohavensis. 

E.  Citellus  {Citellus)  citellus. 

F.  Citellus  (Citellus)  fulvus. 

G.  Cynomys   (Cynomys)    ludovicianus. 
H.  Citellus  {Citellus)  parryii. 

228 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


Plate  14 


Skulls  of  citellus  and  cynomys. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture.  Biological  Survey 


PLATE    15 


Skulls   of    Glaucomys.    tamias.    Eutamias.    Sciurus,    Microsciurus     and 

ClTELLUS. 


Plate  15 
(Natural  size) 

A.  Olaucomys  volans  volans. 

B.  Tamias  striatus. 

C.  Eutamias   (Neotamias)  dorsaUs. 

D.  Microsciurtis  browni. 

E.  Citellus  {AmiHOspennophilus}  harrisii. 

F.  Citellus  iOtoftpermophilus)  variegatus  grammurus. 

G.  Seiurus  ( HeHprrosriuni-s)grixrux. 
H.  Sciurus   (Neosciurus)   carolinensis. 

229 


Plate  16 

(Natural  size) 

A.  Syntheosciunis  brochns. 

B.  Sciurus  (GuerlingMetus)  aestuans  cMriquensis. 

C.  Sciurus    (Parasciurus)    niger  limitis. 

D.  Tamiasciurus  douglasii. 

E.  Sciurus   (Otosciurus)   aberti. 

F.  Sciurus   (Sciurus)   vulgaris. 

230 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE    16 


Skulls  of  Sciurus,  Tamiasciurus,  and  Syntheosciurus. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE    17 


Skulls  of  citellus  and  cynomys 


Plate  17 


(Natural  size) 

A.  Citellus  (CalJosprrDiopJiiltis)   saturatus- 

B.  CitvUu.'i    iPoliofitcllKs)    fnmkUiiii. 

C.  Citellus   (Ictidonn/s)    tritlecemliiicatus. 

D.  Citcllua   ( Xcrosprrniopli ilus)   mohavensis. 

E.  Citellus  iCitrllii.s)  citrlhis. 

F.  Citellus   {Citellus)   fulrus. 

G.  Cynomys   (Cytioinys)    ludorieiainis. 
H.  Citellus    {Citellus)    pnrryii. 


231 


Plate  IS 
(Natural  size) 

A.  Glaucomys  voians  volaiis. 

B.  Tamias  striatus. 

C.  Eutaniias   (Neotamias)    dorsalis. 

D.  Microsciurtis  hrowni. 

E.  Citellus   {Aminospermopliilus)    harrisii. 

F.  Citellus   (OtospermopJiilus)   variegatus  grammnrus. 

G.  Sciiirus    (Hesperosciurus)    griseus. 
H.  Sckirus   (Neosciiirus)   carolinensis. 

232 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture.  Biological  Survey 


PLATE    18 


Skulls   of    Glaucomys.   tamias.    eutamias.    Sciurus,    Microsciurus,    and 

ClTELLUS. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE    19 


SKULLS   OF    SCIURUS.    TAM  I  ASCI  URUS,    AND   SYNTHEOSCI  U  RUS. 


Plate  19 

(Natural  size) 

A.  Synthcosciuriis  brochus. 

B.  Sciurus  {G-uerlinguetus)  aestuans  chiriquensis. 

C.  Sciurus  (Parasciurus)  niger  limitis. 

D.  Tamiasciurus  douylasii. 

E.  Sciurus  {Otosciurus)  abcrti. 

F.  Sciurus   (Sciurus)  vulgaris. 

233 


Plate  20 

(Natural  size* 

A.  Cynomys  (Ci/noniys)  ludoviciantis. 

B.  Citellus  {Xerospermophiliis)  mohavensis. 

C.  Citellus  (CallospermophUus)  saturatiis. 

D.  Citelhis  {Citellus)  citellus. 

E.  Citellus  (Poliocitellus)    franklinii. 

F.  Citellus  (Citellus)   parryii. 

G.  Citellus  (Citellus)  fulvus. 

H.  Citellus  (Ictidomys)  tridecemlineatus. 
234 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


Plate  20 


^^^^^^m                   '*  ^^^^1 

^^^^^^r                    "*  fl 

^^^^^^^^^^^^^r                           ^^1 

^r        ^  1 

^^^V        '-'^  fl 

H^^^^^B                        I^^^H 

M 

^^^^^m              ^%*3^^B 

^^^1 

^^^H 

^^v           "*        .^^H 

H 

UJ 

1 

North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


Plate  21 


Plate  21 
(Natural  size) 

A.  Sciiirus    (Hcipcrosci lints)    grincuH. 

B.  Microsci lints   hroinii. 
V.  Glaiicomys  volans. 

D.  Citellits  (AniiiiospennopJiilus)  han-isii. 

E.  Tamias  stiiaiiix. 

F.  i^ciitrus   (Xcoxciiinis)  caroJiurnsis. 

G.  CltelluH  {Otoxiicniiit/jhiliis)    ritrietjatita  ijnniuininis. 
H.  Eutaniias  (NvotumiiDi)   dorsalis. 

235 


Plate  22 

(Natural  size) 


A.  Bciurus  (Otosciunis)  aberti. 

B.  Sciurus   (Parasciiirtis)   niger. 

C.  Syntheoscmrus   hrochus. 

D.  Sciurus  (Sciurus)  rulgaris. 

E.  Tamiasciurus  dougJasii. 

F.  Sciurus    (Guerlinguetiis)   aestuaus. 

236 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE    22 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE  23 


Skulls  of  citellus. 


Plate  23 

(Natural  size) 

'A.  Citelhis  toinisevdii  niolli.'i.  S   ad.,  Fairfield,  Utah  (no.  30144,  U.  S.  Natl.  Mus., 
Biological   Survey   collection ) . 

B.  Citcllus   idahoriisi.s.    $    ad..    Nanipa.    Idaho    (no.    lG8r.ll,    IT.   S.    Natl.   Mus., 

Biological    Survey   collection). 

C.  Citcllus  va.fhiii!/t()iii  inixhiiKjtoiii.    S    ad..  Wallnla.  Wa.'^h.    (no.  Li:>r)732,  U.  S. 

Natl.  Mu.s.,  Biological   Survey  collection). 

D.  Citcllus  hruinicus,    S    ad.,  Weiser,   Idaho   (no.  201725.  U.  S.  Natl.  Mu.x.,  Bi- 

ological Survey  collection). 

E.  Citcllus   bcldin(/i   htltliii(/i.    S    ad.,   Mannuoth   Pass,   Calif,    (no.   42025.   U.   S. 

Natl.  Mus.,  Biological  Survey  collection). 

F.  Citcllus  avmatus.    6    ad.,   Barclay,   Utah    (no.  87791,   U.   S.   Natl.   Mu.>^.,    Bi- 

ological Survey  collection). 

237 


Plate  24 

(Natural  size) 

A.  Citcllus   colunibknms   coJumhianus,    $    ad.,   Nelson,   British   Columbia    (no. 

66670,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

B.  Citellus  parryii  li/iatiis,   S   ad.,  St.  Lawrence  Island,  Bering  Sea  (no.  57312, 

Mus.  Vert.  Zool.). 

C.  Citellus  osgoodi,    S    ad.,  Circle.  Alaska    (no.  128269,   U.   S.  Natl.  Mus.,   Bi- 

ological Survey  collection). 

D.  Citellus  parryii  t)lesius,   S  ad..  Head  of  Coal  Creek,  Yukon  (no.  134954,  U.  S. 

Natl.  Mus.,  Biological  Survey  collection). 
238 


North  American  Fauna  No.  56.  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


Plate  24 


SKULLS   OF   CITELLUS. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


Plate  25 


SKULLS   OF   CITELLUS. 


Plate  25 

(Natural  size) 

A.  CifellKX  spilosoDW  npilosonxi.    $    ad..  Chicalote.  Agnasoalientes,  Mexico    (no. 

78!t97,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

B.  Citellii-s  spUosomn  prattiisi.s,    3    sul)adult,  Flagstaff,  Ariz.    (no.  202123,  U.  S. 

Natl.  Miis.,  liioldgical   Survey  collection). 

C.  CitcUiis  mcrirdiitis  m<xiruiii(.s,   S    ad.,  Silao,  Guanajuato,  Mexico  (no.  79018, 

U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

D.  Citelhis  peroten.'iis,    $   ad..  Perote,  Vera  Cruz   (no.  54265,  U.  S.  Natl.  Mus., 

Biological   Survey   collection). 

E.  CitcUuK:  rirhanhsoiiii  clef/tuis.    S    ad..  Pinedale,  Wyo.   (no.  176905,  U.  S.  Natl. 

Mus.,  Biological  Survey   collection). 

F.  Citelhis    richdfd.sonii    ricliiird.sonii.     £     ad..    Wingard.    Sask.-itchewan     (no. 
7:>644.  U.  S.  Natl.  Mus.,  Biological  Survey  coll<>etion). 

239 


Plate  26 

(Natural  size) 

A.  Citelhts  ieecheiji  parvidus,    $    subadult.  Loue  Pine,  Calif,   (no.  32553,  U.  S. 

Natl.  Mus.,  Biological  Survey  collection). 

B.  Citelliis   beechei/i   douglasii,    $    acL,   Forest  Grove,   Oreg.    (no.  30887,   U.   S. 

Natl.  Mus.,  Biological  Survey  collection). 

C.  Citellus  varleyatus  rupestris,   2   ad.  (type),  Rio  Sestin.  Durango   (no.  21231, 

Amer.  Mus.  Nat.  Hist.). 

D.  Citellus  cumulatus  atnndatus,   $  ad.,  Manzanillo,  Colima.  Mexico  (no.  44596, 

U.  S.  Natl.  Mus.,  Biological  Survey  collection). 
240 


North  American  Fauna  No.  56.  U.  S.  Dept.  of  Agriculture.  Biological  Survey 


Plate  25 


SKULLS   OF    CITELLUS. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE  27 


SKULLS   OF   CITELLUS. 


F'late  27 
(Natural  size) 

A.  CitcUiis  lateralis  mitratus,    S    ad.,  South  YoUa  Bolly  Mountain,  Calif,   (no. 

138124,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

B.  Citellus  ntadrciisis,  S  ad.,  Sierra  Madre.  near  Guadalupe  y  Calvo.  Chihuahua. 

Mexico   (no.  95357,  U.  S.  Natl.  Mus..  Biological  Survey  collection). 

C.  Citellus    tercticaiulus    tcrcticaiidiis,    $     ad..    Fort    Yuma,    Calif,    (no.    99507, 

U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

D.  Citellus  lateralis  lateralis,  S   ad.,  Hahn.s  Peak.  Colo.   (no.  168865,  U.  S.  Natl. 

Mu8.,  Biological  Survey  collection). 

E.  Citellus  adocefus,    $    ad.,"  La   Salada.  Michoacan.  Mexico   (no.  126140,  U.   S. 

Natl.  Mus.,  Biological  Survey  collection). 

F.  Citellus  leueurus  leuvurns,    $    ad.,  Caltazon.   Calif,    (no.   54010,   U.   S.  Natl. 

Mus.,  Biological  Survey  collection). 

241 


Plate  28 
(Natural  size) 

A.  CiteUiis  toinisendii  mollis,  S  ad.,  Fairfield,  Utah,  (uo.  30144,  U.  S.  Natl.  Mus., 

Biological  Survey  collection). 

B.  Citellus,  idalioeiisis,    $    ad..   Nampa,   Idaho    (no.   168511,   U.   S.   Natl.   Mus., 

Biological  Survey  collection). 

C.  Citellus  icashiuytoni  ivashiufftoni,    $    ad.,  Wallula,  Wash.    (no.  235732,  U.  S. 

Natl.- i\Ius.,  Biological  Survey  collection). 

D.  Citellus  bruiiHeus,    $    ad.,  Weiser,  Idaho   (no.  201725,  U.  S.  Natl.  Mus.,  Bi- 

ological Survey  collection). 

E.  Citellus   heldiufii   heldiiigi,    $    ad..  Mammoth  Pass,  Calif,    (no.   42025,  U.  S. 

Natl.  Mus.,  Biological  Survey  collection). 

F.  Citellus  armatus,   $  ad.,  Barclay,  Utah  (no.  87791,  U.  S.  Natl.  Mus.,  Biologi- 

cal Survey  collection). 
242 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE   28 


SKULLS  OF  CITELLUS. 


N  orth  American  Fauna  No.  56.  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE  29 


SKULLS  OF   ClTELLUS. 


Plate  29 

(Natural  size) 

4.  Citellus   columbianus   coliiiiihiniiitx.    $    ad..    Nelson.    British   Columbia    (no. 
66670,  U.  S.  Natl.  Mas.,  Biological  Survey  collection). 

B.  Citellus  parry  a  lyratiis,   $   ad.,  St.  Lawrence  Island,  Bering  Sea  (no.  57312, 

Mus.  Vert.  Zool.). 

C.  Citellus  osffoodi,   S    ad.,  Circle,  Alaska   (  no.  128369,  U.  S.  Natl.  Mus..  Biological 

Survey  collection). 

D.  Citellus  parry  a   plesius,    $    ad..   Head  of  Coal   Creek.   Yukon    (no.   134954, 

U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

243 


Plate  30 

(Natural  size) 

A.  CiteUiis  spilosoma  spilosoma,   $    ad.,  Chicalote.  Agiiascalientes,  Mexico   (no. 

78997,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

B.  Citelltis  spilosoma  pratensis,    S   subadult,  Flagstaff,  Ariz.   (no.  202123,  U.  S. 

Natl.  Mus.,  Biological  Survey  collection). 

C.  Citelltis  mejcicanus  mexicanus,   S   ad.,  Silao,  Guanajuato,  Mexico  (no.  79108, 

U.  S.  Natl.  Mus..  Biological  Survey  collection). 

D.  Citellus  perotensis,    $    ad.,  Perote,  Vera  Cruz   (no.  54265,  U.  S.  Natl.  Mus., 

Biological  Survey  collection). 

E.  Citellus  richardsonii  elegans,   S  ad.,  Piuedale,  Wyo.  (no.  176905,  U.  S.  Natl. 

Mus.,  Biological  Survey  collection). 

F.  Citellus    richardsonii    richardsonii,     $    ad.,    Wingard.    Saskatchewan     (no. 

73644,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 
244 


North  American  Fauna  No.  56.  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


Plate  30 


A 

B 

c 

A  .    & 

D 

%^ 

^ry 

A 

■^"^1 

^  ^  -^ 

'■**' 

^^^^^^H 

SKULLS  OF  CITELLUS. 


North  American  Fauna  No.  56,  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE   3t 


SKULLS   OF   CITELLUS. 


Plate  31 

(Natural  size) 

A.  Citc1lii.<<  hecrhciii  iKirnilii-s.    £    subadiilt.  Lone  Pine.  Calif,    (no.  32o5?),  U.   S. 

Natl.  Mn.s.,  Biological  Survey  collection). 

B.  Citellus  beech fiji  doiiijlaaii,  S   ad.,  Forest  Grove,  Oreg.   (no.  30S87,  U.  S.  Natl. 

Mus.,  Biological  Survey  collection  ) . 

C.  Citellus  rarief/otiix  rupeHtriH,   $   ad.  (type),  Rio  Sestin.  Durango   (no.  21231, 

Amer.   Mus.   Nat.    Hist.). 

D.  Citellus  animhitus  aiiuiilatus.   S   ad.,  Manzanillo,  Colinia.  Mexico  (no.  44-596, 

U.  S.  Natl.  :Mus.,  Biological  Survey  collection). 

245 


Plate  32 

(Natural  size) 

A.  Citellus  lateralis  mitratus,    $    ad.,  South  YoUa  Bollv  Mountain,  Calif,   (no. 

138124,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

B.  Citellus  madrensis,  $  ad.,  Sierra  Madre,  near  Guadalupe  y  Calvo,  Chihuahua, 

Mexico  (no.  95357,  U.  S.  Natl.  Mus.,  Biological  Survey  collection). 

C.  Citellus    tereticaudus    tereticaudus,    $    ad.,    Fort   Yuma,    Calif,    (no.   99507, 

TJ.  S.  Natl.  Mus.,  Biological  Survey  collection). 

D.  Citellus  lateralis  lateralis,  $  ad.,  Hahus  Peak,  Colo.  (no.  168865,  U.  S.  Natl. 

Mus.,  Biological  Survey  collection). 

E.  Citellus  adocctus,    $    ad..  La  Salada,  Michoacan,  Mexico    (no.  126140,  U.  S. 

Natl.  Mus.,  Biological  Survey  collection). 

F.  Citellus  leucurus  leucurus,    $    ad.,  Cabazon,  Calif,    (no.  54010,  U.   S.  Natl. 

Mus.,  Biological  Survey  collection). 
246 


North  American  Fauna  No.  56.  U.  S.  Dept.  of  Agriculture,  Biological  Survey 


PLATE   32 


SKULLS  OF  CITELLUS. 


INDEX 


[New  names  and  principal  page  references  to  a  species  in  boldface;  synonyms  in  italic] 


aberti,  Sciurus,  49,  50. 
ablusus,  Citellus  parrvii,  17,  54,  95,  97, 
98,  100,  101,  102,  103. 

Citellus  plesius,  98. 
Acknowledgments,  2. 
adocetus,  Citellus,  29  (habits),  44,  164, 
165. 

Otospermophilus,  165. 
adolphei,  Sciurus,  49. 
aestuans,  Sciurus,  50. 
albertae,  Citellus  columhianus,  85,  88. 
alfari,  Microsciurus,  51. 

Sciurus,  51. 
alleni,    Citellus    tridecemlineatus,    113, 
114,  115,  116,  117,  118. 

Sciurus,  50. 

Spermophilus  tridecemlinentus,  114. 
Ainmospermophilus,  5,  29  (habits),  30, 
35,  39,  44,  45,  53,  54,  166,  182. 

amplus,  182,  183. 

canfieldae,  178. 

cinnamomeus,  174. 

extimus,  179. 

harrisii,  167. 

insularis,  181. 

interpres,  180. 

kinoensis,  169. 

leucurus,  170. 

nelsoni,  182. 

peninsulae,  176. 

pennipes,  175. 

saxicola,  169. 

tersus,  173. 
amplus,  Ammospermophilns  nelsoni,  182, 

183. 
Anisonyx,  53. 

brachinra,  53,  55,  85. 

canescens,  125. 

cinnamomeus,  174. 

cryptospilotus,  130. 

grammurus,  142. 

harrisii,  167. 

macros  pilotus,  125. 

tereticaudus,  187. 
annectens,  Citellus  spilosoma,  128. 

S pernio philus  spilosoma,  128. 
annulatuK,  Citellus,  28  (habits),  29,  39, 
46,  55,  162. 

Citellus  annulatus,  163,  164,  165. 

Notocitellus,  46. 

Otospermophilus,  163. 

Spermophilus,  44,  55,  163. 
Antelope  scjuirrel,  5,  29  (liabits),  35,  39, 
54. 

Colorado,  175. 

Espiritu  Santo,  181. 


Antelope  squirrel — Continued. 

Grand  Canyon,  173. 

gray-tailed,  167. 

mid-peninsular,  178. 

rusty,  174. 

San  Joaquin,  182. 

southern  peninsular,  179. 

Texas,  180. 

western  peninsular,  176. 

white-tailed,  170. 

Yuma,  169. 

See    also    Ground    squirrel.    Rock 
squirrel. 
apache,  Sciurus,  50. 
apricus,  Citellus  tereticaudus,  190. 
Araeosciurus,  50. 
Arctomys,  53,  55. 

beecheyi,  55,  148. 

brachyura,  85. 

brachyurus,  85. 

columbianns,  53,  55,  85. 

douglasii,  55,  150. 

erytkrogluteia,  55,  85,  88,  97. 

franklinii,  42,  133. 

hoodii,  55,  107. 

kennicottii,  55,  91,  94. 

lateralis,  191. 

parryi,  88,  91. 

phaeognatha,  55,  91. 

richardsonii,  73. 

tridecemlineata,  107. 
arenicola,  Citellus  tridecemlineatus,  111, 

113,  116,  118. 
arens,  Spermophilus  spilosoma,  125. 
arizonae,  Citellus  tereticaudus,  187,  188. 
arizonensis,   Callospermophilus  lateralis^ 
196.      ■ 

Citellus  lateralis,  191,  193,  196,  214. 

Sciurus,  50. 
armatus,  Citellus,  10  (habits),  54,  78,  82, 
83,  85. 

Spermophilus,  55,  56,  78. 
artemesiae,  Citellus  mollis,  63,  65. 

Citellus  townsendii,  64,  65. 
asiaticus,  Eutamias,  47. 

Sciurus  striatus,  47. 
atricapillus,  Citellus,  160,  161. 

Citellus  variegatus,  161. 

Otospermophilus  grammurus,  161. 

Spermophilus  grammurus,  161. 
aureogaster,  Sciurus,  49. 

badius,  Ictidomys  tridecemlineatus,   110. 
Spermophilus  tridecemlineatus,  110, 
111. 
Baiosciurus,  49. 

247 


248 


NORTH  AMERICAN  FAUNA 


[No.  56 


barrowensis,  Citellus  parryii,  94,  95,  99. 

Sper^nophilus,  95. 
beecheyi,  Arctomys,  55,  148. 

Citellus,  5,  26,  43,  44,  133. 

Citellus  beecheyi,  23  (habits),  28, 
148,  151,  152,  153,  154,  155,  157, 
158,  159,  160,  161,  162. 

Citellus  grammurus,  148. 

Citellus  variegatus,  148. 

Otospermophilus,  44,  148. 

Otospermophilus  grammurus,  148. 

Spermophilus,  148. 

Spermophilus  grammurus,  148. 
beldingi,  Citellus,  40,  54,  81. 

Citellus  beldingi,  11  (habits),  81, 
83,  84. 

Spermophilus,  56,  81. 
bensoni,  Citellus,  215. 
beringensis,  Citellus  parryii,  96. 

Spermophilus,  95. 
bernardinus,  Callospermophilus,  209. 

Citellus  chrysodeirus,  209. 

Citellus  lateralis,  204,  209. 

Spermophilus,  209. 
boothiae,  Sciurus,  49. 
boquetensis,  Microsciurus,  51. 
hrachiura,  Anisonyx,  53,  55,  85. 
hrachyura,  Arctomys,  85. 
brachyurus,  Arctomys,  85. 
brevicaudus,   Spermophilus    chrysodei- 
rus, 209. 
brochus,  Syntheosciurus,  52. 
brunneus,  Citellus,  71,  72. 

Citellus  townsendii,  72. 
Bubonic  plague,  10,  11,  13,  16,  26. 
buccatus,  Sciurus,  136. 
buckleyi,   Citellus   variegatus,   43,    141, 
144. 

Otospermophilus  grammurus,  141. 

Spermophilus,  55,  141. 

Spermophilus  grammurus,  141. 
buxtoni,  Citellus,  3,  100,  102. 

Citellus  parryii,  100. 

Callospermophilus,   5,   31    (habits),   35, 
39,  45,  53,  54,  190,  215. 

arizonensis,  196. 

bernardinus,  209. 

caryi,  197. 

castanurus,  201. 

certus,  208. 

chrysodeirus,  203,  215,  216. 

cinerascens,  198,  199. 

connectens,  205. 

lateralis,  43,  192. 

madrensis,  213. 

mitratus,  210. 

perpallidus,  206,  207. 

saturatus,  212. 

tescorum,  199. 

trepidus,  206. 

trinitatis,  211. 

wortmani,  195. 
canescens,  Anisonyx,  125. 

Citellus  spilosoma,  124,  125,  126, 
129. 

Spermophilus,  125. 

Xerospermophilus,  125. 


canfieldae,  Ammospermophilus  leucurus, 
178. 

Citellus  leucurus,  177,  178,  179. 
canus,  Citellus  mollis,  67. 

Citellus    townsendii,     61,     64,    66, 
67,  71. 

Spermophilus  mollis,  67. 
captus,  Citellus  beecheyi,  216. 
carolinensis,  Neosciurus,  51. 

Sciurus,  48,  49,  50,  51. 
caryi,  Callospermophilus  lateralis,  197. 

Citellus  lateraUs,  193,  195,  197,  202. 
castanurus,  Callospermophilus,  201. 

Citellus,  201. 

Citellus  lateralis,  192,  193,  197,  198, 

199,  201,  203,  205,  207. 
Spermophilus,  201. 
Tamias,  201. 

certus,  Callospermophilus  lateralis,  208. 

Citellus  laterahs,  204,  208. 
Chickaree,  51. 
Chipmunk,  35,  52. 

eastern,  46,  47. 

western,  47. 
chlorus,  Citellus,  188. 

Citellus  tereticaudus,  188. 
chrysodeirus,    Callospermophilus,    203, 
215,  216. 

Citellus,  203,  215,  216. 

Citellus  lateralis,  194,  198,  203,  205, 
207,  208,  209,  210,  211,  212,  213. 

Spermophilus,  203. 

Tamias,  203. 
cinerascens,  Callospermophilus,  198,  199. 

Citellus,  198,  199. 

Citellus  laterahs,  192.  197.  198.  190. 

200,  201,  202. 
Spermophilus,  198. 
Tamias,  198. 
Tamias  lateralis,  198. 

cinereicollis,  Eutamias,  48. 
cinnamomeus,    Amm,ospermophilus    leu- 
curus, 174. 

Anisonyx  leucurus,  174. 

Citellus  leucurus,  167,  168,  171,  172, 
173,  174,  175,  176,  180,  181,  182. 

Spermophilus  leucurus,  174 

Tamias  leucurus,  174. 
citellus,  Citellus,  2,  40,  54. 

Mus,  39,  40,  53. 
Citellus,  39  (genus),  40  (subgenus). 

ablusus,  17,  54,  95,  97,  98,  100,  101, 
102,  103. 

adocetus,  29  (habits),  44,  164,  165. 

albertae,  85,  88. 

alleni,  113,  114,  115,  116,  117,  118. 

annectens,  128. 

annulatus,  28  (habits),  29,  39,  46. 
55,  162,  163,  164,  165. 

apricus,  190. 

arenicola,  111,  113,  116,  118. 

arizonae,  187,  188. 

arizonensis,  191,  193,  196,  214. 

armatus,    10    (habits),    54,   78,   82, 
83,  85. 

artemesiae,  63,  64,  65. 

atricapillus,  160,  161. 

barrowensis,  94,  95,  99. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


249 


Citellus — Continued. 

beecheyi,  5,  23  (habits),  26,  28,  43, 
44,  133,  148,  151,  152,  153,  154, 

155,  157,  158,  159,  160,  161,  162. 
beldingi,    11    (habits),    40,    54,    81, 

83,  84. 
bensoni,  215. 
beringensis,  96. 
bernardinus,  204,  209. 
brunneus,  71,  72. 
bucklevi,  43,  141,  144. 
buxtoni,  3,  100,  102. 
canescens,  124,  125,  126,  129. 
canfieldae,  177,  178,  179. 
canus,  61,  64,  66,  67,  71. 
captus,  216. 

carvi,  193,  195,  197,  202. 
castanurus,  192,  193,  197,  198,  199, 

201,  203,  205,  207. 
certus,  204,  208, 
chlorus,  188. 
chrvsodeirus,    194,    198,    203,    205, 

207,  208,  209,  210,  211,  212,  213, 

215,  216. 
cinerascens,  192,  197,  198,  199,  200, 

201,  202. 
cinnamomeus,    167,    168,    171,   172, 

173,  174,  175,  176,  180,  181,  182. 
citellus,  2,  40,  54. 
cochisei,  215. 
columbianus,  5,  13  (habits),  54,  85, 

89,  90,  98. 
connectens,  201,  205. 
couchi,  140. 

couchii,  137,  138,  139,  141,  143. 
cryptospilotus,  129,  130. 
douglasi,  150. 
douglasii,  27  (habits),  148,  150,  155, 

216. 
elegans,  5,  10  (habits),  11,  68,  74, 

75,  76,  77,  79,  80,  81,  82,  83,  132. 
eremonomus,  185,  186. 
erythrogluteius,  97,  98. 
eversmanni,  54. 
extimus,  177,  178,  179,  181. 
fisheri,  28,  150,  151,  152,  153,  154, 

156,  157,  158,  216. 
franklini,  133. 

franklinii,  3,  5,  21  (habits),  41,  42, 

43,  44,  133,  215. 
fulvus,  54. 
goldmani,  164. 
grammurus,  23,  43,  45,  55,  137,  139, 

140,  141,  142,  146,  147,  148. 
guttatus,  71. 
harrisi,  167. 

harrisii,  167,  170,  171,  172. 
hollisteri,  115,  117. 
idahoensis,   6   (habits),  54,  63,   68, 

69,  72. 
insularis,  164,  181. 
interpres,  169,  176,  180. 
juglans,  142,  144. 
kadiacensis,  103. 
kennicotti,  91. 
kennicottii,  91. 


Citellus — Continued. 

kodiacensis,  97,  99,  100,  103. 
laterahs,  43,  55,  191,  195,  196,  197, 

198,  201,  202,  203,  212,  213,  214. 
leucurus,   168,   169,   170,   173,   174, 

175,  176,  177,  178,  179,  180,  182. 
leurodon,  63,  64. 
loringi,  71. 

lyratus,  97,  99,  101,  103. 
macrospilotus,  125. 
madrensis,  46,  191,  213. 
major,  126,  128,  129,  130,  131. 
mexicanus,  5,  20  (habits),  41,  42,43, 

54,  119,  121,  122,215,  216. 
microspilotiis,  125. 
mitratus,  204,  210,  212. 
mohavensis,  30  (habits),  183,  185. 
mollis,  5,  6,  7,  45,  54,  63,  65,  66,  67, 

68,  72,  106,  183,  184,  185,  186. 
monticola,  116,  118. 
nebulicola,  100,  102. 
neglectus,  186,  187. 
nelsoni,  182. 
nesioticus,  160. 
nevadensis,  77,  79. 
nudipes,  150,  157,  158,  160. 
obsoletus,  127,  130. 
oregonus,  5,  12  (habits),  41,  43,  77, 

79  80    82   83. 
osgoodi',  17  (habits),  54,  92,  98,  104. 
pallescens,  124,  125,  126,  132. 
pallidus,  109,  111,  112,  115,  118. 
parry i,  91. 
parrvii,  3,  16  (habits),  38,  39,  54, 

5o,  90,  91,  95,  96,  97,  98,  99,  100, 

104,  105,  136. 
parvidens,  119,  121. 
parvulus,   150,   155,   156,   158,   159, 

160. 
parvus.  113,  115,  117. 
peninsulae,  166,  176,  178,  179. 
pennipes,  175. 
perotensis,  21,  41,  42,  132. 
pessitnus,  65. 
plesius,  16,  17,  86,  87,  88,  92,  97,  99, 

100,  105,  133. 
pratensis,  128,  130. 
quatalensis,  214,  215. 
richardsoni,  73. 
richardsonii,  5,  8  (habits),  54,  73, 

76,  77,  78,  79,  81,  85,  86. 
ridgwayi,  215. 
ruficaudus,  88,  89. 
rupestris,  137,  138,  140,  141,  144. 
rupinaruni,  159. 
saturatus,  191,  203,  212. 
saxicola,  169. 
sierrae,  153,  155. 
spilosoma,  5,  20  (habits),  31,  41,  42, 

55,  70,   120,   122,   124,   126,   131, 
132. 

stejnegeri,  3. 
slonei,  98,  100. 
taylori,  216. 

tereticaudus,    30    (habits),    41,    45, 
184,  185,  187,  189,  190. 


250 


NORTH  AMERICAN  FAUNA 


[No.  56 


Citellus — Continued. 

tersus,  173. 

tescoriim,  198,  199,  206,  212,  213. 

texensis,  107,  109,  110,  111,  122. 

townsendi,  216. 

townsendii,  5  (habits),  55,  60,  69, 
70   71   73 

trepi'dus,'  201,  202,  204,  206,  208. 

tridecemlineatus,  3,  5,  18  (habits), 
21,  31,  41,  42,  54,  106,  107,  110, 
113,  115,  118,  119,  216. 

trinitatis,  210,  211. 

tuitus,  215. 

tularosae,  145. 

Utah,  144,  146. 

variegatus,  22  (habits),  54,  55,  136, 
138,  140,  146. 

vigilis,  61,  66,  67,  68. 

vinnulus,  170. 

vociferans,  185,  186. 

Washington!,  5,  6,  7  (habits),  54,  62, 
63,  69,  71,  72,  73,  106,  107,  216. 

washoensis,  63,  64. 

wortmani,  191,  193,  195. 

yakimensis,  60,  63. 
Citillus,  53. 

mexicanus,  119. 
citillus,  Mus,  53. 
cochisei,  Citellus,  215. 
coUiaei,  Sciurus,  49. 
Colobates,  53. 
Colobotis,  53,  54. 

columbianus,  85. 

franklinii,  54. 

hoodii,  54. 

kennicotti,  91. 

parry i,  91. 

richardsonii,  54. 

tridecemlineatus,  54. 
Colored  plates,  explanation  of,  2. 
columbianus,  Arctomys,  53,  55,  85. 

Citellus,  5,  13  (habits),  54,  85,  98. 

Citellus  columbianus,  85,  89,  90. 

Colobotis,  85. 

Spermophilus,  85. 
concolor,  Sciurus,  50. 
connectens,    Callospermophilus    chryso- 
deirus,  205. 

Citellus  lateralis,  201,  205. 
couchi,  Citellus  variegatus,  140. 
couchii,    Citellus    variegatus,    137,    138, 
139,  141,  143. 

Otospermophilus,  grammurus,  140. 

Spermophilus,  55,  139. 

Spermophilus  grammurus,  139. 
Cranial  measurements,  explanation  of, 

59. 
cryptospilotus,  Anisonyx,  130. 

Citellus  spilosoma,  129,  130. 

Spermophilus,  130. 

Xerospermophilus,  130. 
Cynomys,  35,  38,  39. 

gunnisoni,  55,  88. 

ludovicianus,  38. 

socialis,  38. 


deppei,  Sciurus,  49. 
Diseases — 

Bubonic  plague,  10,  11,  13,  16,    26. 

Rocky  Mountain  spotted  fever,  16. 

Tularemia,  6,  26,  27. 
dorsalis,  Eutamias,  48. 
douglasi,  Citellus  beecheyi,  150. 

Citellus  variegatus,  150. 
douglasii,  Arctomys,  55,  150. 

Citellus,  216. 

Citellus  beecheyi,  27  (habits),  148, 
150,  155. 

Otospermophilus  grammurus,  151. 

Spermophilus,  150. 
douglassi,  Spermophilus  grammurus,  150. 
durangi,  Sciurus,  50. 

Echinosciurus,  48,  49. 
elegans,  Citellus,  10,  11,  76. 

Citellus  richardsonii,  5,  10  (habits), 
68,  74,  75,  76,  77,  79,  80,  81,  82- 
83,  132. 

Spermophilus,  55,  56,  62,  76. 

Spermophilus  richardsoni,  76. 
empetra,  Mus,  91. 

Spermophilus,  56,  91. 
eremonomus,  Citellus,  185,  186. 
erythroglutaeus,    Spermophilus    empetra, 

85. 
erythrogluteia,  Arctomys,  55. 

Arctomys  parryi,  85,  88,  97. 

Spermophilus  parryi,  85. 
erythrogluteius,  Citellus,  97,  98. 
Eutamias,  35,  39,  44,  46,  47,  52. 

asiaticus,  47. 

cinereicollis,  48. 

dorsalis,  48. 

frater,  48. 

sonomae,  48. 
eversmanni,  Citellus,  54. 

Spermophilus,  53. 
extimus,    Ammospermophilus   leucurus, 
179. 

Citellus  leucurus,  177,  178, 179, 181. 

Fever,  Rocky  Mountain  spotted,  16. 
fisheri,  Citellus  beecheyi,  28,  150,   151, 
152,  153,  154,  156,  157,  158,  216. 

Citellus  variegatus,  154. 

Otospermophilus   grammurus,    154. 

Spermophilus  beecheyi,  154. 

Spermophilus  grammurus,  154. 
Flying  squirrel,  35,  52. 
Fossil  species,  214. 
Fox  squirrel,  34,  50. 
franklini,  Spermophilus,  133. 
franklinii,  Arctomys,  42,  133. 

Citellus,  3,  5,  21  (habits),  41,  42, 
43,  44,  133,  215. 

Colobotis,  54. 

Poliocitellus,  43,  44. 

Spermophilus,  133. 
frater,  Eutamias  quadrivittatus,  48. 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


251 


fulvus,   Citellus,   54. 

Spermophilus,  53,  54. 

Geographic  distribution,  2. 

gerrardi,  Sciurus,  51. 

gidleyi,  Otospermophilus,  215. 

Glaucomys,  35,  52. 

goldmani,  Citellus  annulatus,  164. 

Otospermophilus  annulatus,  164. 

Sciurus,  49. 

Spermophilus  annulatus,  164. 
grammurus,  Anisonyx,  142. 

Citellus,  43,  45,  55. 

Citellus  grammurus,  142. 

Citellus  variegatus,  23,  43,  137,  139, 
140,  141,  142,  146,  147,  148. 

Otospermophilus,  142. 

Otospermophilus  grammurus,  142. 

Sciurus,  43,  53,  142. 

Spermophilus  grammurus,  142. 
Gray  gopher,  21. 
Gray  squirrel,  eastern,  34. 

western,  34. 
griseoflavus,  Sciurus,  49. 
griseus,  Sciurus,  49,  50. 
Ground  hog,  37. 
Ground  squirrel,  Aleutian,  98. 

antelope,  5,  29  (habits),  54. 

Apache  spotted,  125. 

Arizona  mantled,  196. 

Arizona  round-tailed,  187. 

Arizona  striped,  116. 

Barrow,  95. 

Belding's,  11  (habits),  81. 

Bennett's  spotted,  122. 

Bighorn  striped,  114. 

Blue  Mountains,  89. 

Blue  Mountains  mantled,  205. 

California,  4,  5,  23  (habits),  148. 

Gary's  mantled,  197. 

Cascade  mantled,  212. 

Catalina,  160. 

Catavina,  159. 

Charleston     Mountains     mantled, 
208. 

Columbian,   4,   5,   13   (habits),   55, 
85. 

desert  spotted,  130. 

Douglas's,  5,  27  (habits),  150. 

Fisher's,  154. 

Franklin's,   5,  21    (habits),  39,   55, 
133. 

golden-mantled,  203. 

Goldman's,  28  (habits),  164. 

gray,  3,  67. 

Hoilister's  mantled,  199. 

HoUister's  striped,  115. 

Idaho  spotted,  72. 

Jaurez,  158. 

Kennicott's  spotted,  130. 

Kodiak,  103. 

least  Idaho,  65. 

least  striped,  117. 

lesser  California,  156. 

lesser  tropical,  29  (habits),  165. 


Ground  squirrel — -Continued. 

Loring's,  71. 

Malheur  Vallev,  66. 

mantled,  5,  31  (habits),  35,  39,  54. 

Merriam's  mantled,  198. 

Mexican,  20  (habits),  119. 

Mexican  spotted,  55. 

Mohave,  30  (habits),  183. 

Nevada,  77. 

Nevada  mantled,  206. 

New  Mexico  spotted,  126. 

Oregon,  4,  5,  12  (habits),  83. 

Padre  Island,  128. 

pallid  spotted,  124. 

pallid  striped,  112. 

Palm  Springs,  188. 

park  spotted,  128. 

Parrv's,  16  (habits),  88,  91. 

Perote,  21,  132. 

Piute,  63. 

Richardson's,  4,   5,   8   (habits),   55, 
73. 

ring-tailed,  28  (habits),  39,  163. 

Rio  Grande.  121. 

round-tailed,  5,  30  (habits),  185. 

St.  Lawrence  Island,  101. 

San  Bernardino  mantled,  209. 

sandhill  striped,  111. 

Say's  mantled,  191. 

Shumagin,  100. 

Sierra,  153. 

Sierra  Madre  mantled,  213. 

Snake  Vallev,  6  (habits),  68. 

spotted,  5,  20  (halnts),  39. 

striped,  5,  18  (habits),  39,  55. 

Texas  striped.  110. 

thirteen-lined,  107. 

Townsend's,  5  (habits),  60. 

Trinidad  Valley,  190. 

Trinitv  Mountains  mantled,  211. 

Uinta,'  4,  10  (habits),  78. 

Wasatch  mantled,  201. 

Washington,  5,  7  (habits),  69. 

Wortman's  mantled,  195. 

Wvoming,  5,  10  (habits),  76. 

Yolla  Bolly  mantled,  210. 

Yukon,  97. 

Yukon  Valley,  17  (habits),  104. 

See    also    Antelope    squirrel,    Rock 
squirrel. 
Gucrlinguetus,  50. 
guerlinguetus,  Sciurus,  50. 
gunnisoni,  Cynomys,  55,  88. 

Spermophilus,  38. 
guttatus,  Citellus,  71. 

Spermophilus,  62. 

Habits  and  economic  relations,  4. 
harrisi,  Citellus,  167. 

Tamias,  167,  170. 
harrisii,  Ammospermophilus,  167. 

Anisonyx,  167. 

Citellus  harrisii,  167,  170,  171,  172. 

Spermophilus,  55,  56,  167,  170. 
Hesperosciurus,  34,  49. 


252 


NORTH  AMERICAN  FAUNA 


[No.  56 


hoffmanni,  Sciurus,  51. 

hoUisteri,  Citellus  tridecemlineatus,  115, 

117. 
hoodii,  Arctomys,  55,  107. 

Colobotis,  54. 
hudsonicus,  Sciurus,  51. 

Tamiasciurus,  50. 
hypopyrrhus,  Sciurus  aureogaster,  48,  49. 

Ictidomoides,  41,  53,  54. 
Ictidomys,  39,  41,  42,  53,  54,  106,  215, 
216. 

badius,  110. 

mexicanus,  43. 

tereticaudus,  187. 
idahoensis,  Citellus,  6  (habits),  54,  63, 

68,  69,  72. 
insularis,  Ammospermophilus  leucurus, 
181. 

Citellus,  164,  181. 

Citellus  leucurus,  181. 
nterpres,  Ammospermophilus,  180. 

Ammospermophilus  leucurus,    180. 

Citellus,  169,  176,  180. 

Spermophilus,  180. 

Tamias,  180. 
isthmius,  Microsciurus,  51. 

juglans,  Citellus  variegatus,  142,  144. 

kadiacensis,  Citellus  parry i,  103. 
kaibabensis,  Sciurus,  50. 
kennicotti,  Citellus  parryi,  91. 

Colobotis  parryi,  91. 
kennicottii,  Arctomys,  55,  91,  94. 

Citellus  parryi,  91. 
Keys — 

Ammospermophilus,  167. 

Callospermophilus,  191. 

Citellus,  56,  59. 

Ictidomys,  106. 

Notocitellus,  162. 

Otospermophilus,  135. 

Sciuridae,  36. 

Xerospermophilus,  183. 
kinoensis,    Ammospermophilus    harrisii, 

169. 
kodiacensis,  Citellus,  97,  99,  100,  103. 

Spermophilus  empetra,  103. 

Spermophilus  parryi,  103. 

Spermophilus  parryii,  56. 

lateralis,  Arctomys,  191. 

Callospermophilus,  43,  192. 

Citellus,  43,  55,  192. 

Citellus  laterahs,  191,  195,  196,  197, 
198,  201,  202,  203,  212,  213,  214. 

Sciurus,  45,  53,  191. 

Spermophilus,  56,  191. 

Tamias,  192. 
Leucocrossuromys,  38. 
leucurus,  Ammospermophilus,  170. 

Citellus  leucurus,  168,  169,  170, 
173,  174,  175,  176,  177,  178,  179, 
180,  182. 

Spermophilus,  53,  54,  170. 

Tamias,  44,  170. 
leurodon,  Citellus,  63,  64. 


loringi,  Citellus  Washington!,  71. 

ludovicianus,  Cynomys,  38. 
lyratus,  Citellus,  101. 

Citellus  parryii,  97,  99,  101,  103. 

macrospilotus,  Anisonyx  spilosoina,  125. 

Citellus  spilosoma,  125. 

Spermophilus    spilosoma,    125. 

Xerospermophilus  spilosoma,  125. 
macrourus,  Spermophilus,  55,  136. 
madrensis,  Callospermophilus,  213. 

Citellus,  46,  191,  213. 
major,  Citellus  spilosoma,  126,  128,  129, 
130,  131. 

Spermophilus  spilosoma,  126. 
managuensis,  Sciurus,  49. 
marginatus,  Spermophilus  spilosoma,12Gf 

127. 
Marmot,  35,  36,  37,  38. 

Marmota,  35,  37,  38,  53. 

marmota,  38. 

monax,  38. 
marmota,  Marmota,  38. 

Mus,  37. 
Marmotops,  38. 
merriami,  Tamias  asiaticus,  47. 
Mesosciurus,  50. 

mexicanus,  Citellus,  5,  20,  41,  42,  43,  54. 
215,  216. 

Citellus  mexicanus,  119,  121,  122. 

Citillus,  119. 

Ictidomys,  43. 

Otospermophilus,  119. 

Sciurus,  41,  53,  119. 

Spermophilus,  119. 
Microsciurus,  35,  51,  52. 

alfari,  51. 

boquetensis,  51. 

isthmius,  51. 

septentrionalis,  51. 
microspilotus ,  Citellus  spilosoma,  125. 

Spermophilus  spilosoma,  125. 
mitratus,      Callospermophilus      chryso- 
deirus,  210. 

Citellus  lateralis,  204,  210,  212. 
mohavensis,   Citellus,  30  (habits),   183, 
185,  186. 

Citellus  tereticaudus,  183,  185. 

Spermophilus,  45,  53,  54,  183. 
mollis,  Citellus,  5. 

Citellus  townsendii,  6,  7,  45,  54,  63, 
65,  66,  67,  68,  72,  106,  183,  184, 
185,  186. 

Spermophilus,  55,  62,  63. 

Spermophilus  townsendi,  63. 
monax,  Marmota,  38. 
monticola,     Citellus     tridecemlineatus, 

116,  118. 
Mus  citellus,  39,  40,  53. 

citillus,  53. 

empetra,  91. 

marmota,  37. 

volans,  52. 

nayaritensis,  Sciurus,  50. 
nebulicola,  Citellus,  100. 

Citellus  parryii,  100,  102. 


19381 


REVISION  OF  THE  GROUND  SQUIRRELS 


253 


neglectus,  Citellus,  187. 

Citellus  tereticaudus,  186,  187. 

Spermophilus,  187. 
nelsoni,  Ammospermophilus,  182. 

CiteUus,  182. 

Sciurus,  49. 

Spermophilus,  182. 
Neosciurus,  34,  48,  50. 

carolinensis,  51. 
Neotamias,    47. 
nesioticus,  Citellus,  160. 

Citellus  beecheyi,  160. 

Otospermophilus,   160. 
nevadensis,  CiteUus  elegans,  77. 

CiteUus  richardsonii,  77,  79. 
niger,  Sciurus,  50. 
Notocitellus,  39,  44,  45,  162. 

annulatus,  46. 
nudipes,    Citellus    beecheyi,    150,    157, 
158,  160. 

obsidianus,  Spermophilus  spilosoma,  128. 
obsoletus,  Citellus,  130. 

CiteUus  spnosoma,127,  130. 

Spermophilus,  55,  130. 
oculatus,    Sciurus,    50. 
olivaceus,  Spermophilus  tridecemlineatus, 

112,  113. 
oregoDUS,    Citellus,    83. 

Citellus    beldingi,    5,    12    (habits), 
41,  43,  77,  79,  80,  82,  83. 

Spermophilus,  83. 
osgoodi,    CiteUus,    17    (habits),   54,   92, 
98,  104. 

Spermophilus,  104. 
Otocolobus,  53. 
Otosciurus,  34,  50. 

Otospermophilus,  5,  35,  39,  42,  43,  45, 
48,  53,  135,  164,  215. 

adocetus,  165. 

annulatus,   163. 

atricapiUus,   161. 

beecheyi,    44,    148. 

buckleyi,   141. 

couchii,    140. 

douglasii,  151. 

fisheri,    154. 

gidleyi,  215. 

goldmani,  164. 

grammurus,  142. 

mexicanus,  119. 

nesioticus,   160. 

rupestris,   138. 

tularosae,  145. 

Utah,    146. 

variegatus,    136. 

pallescens,  CiteUus  spilosoma,  124,  125, 

126,  132. 
pallidus,  CiteUus  tridecemlineatus,  109, 
111,  112,  115,  118. 

Spermophilus    tridecemlineatus,    56, 
112. 
Parasciurus,  34,  50,  51. 
parryi,  Arclomys,  88. 
Citellus,  91. 
Colobotis,  91. 
Spermophilus,  91. 


parryii,  Arctomys,  91, 

Citellus,  3,  38,  39,  54,  55,  90,  136. 

CiteUus    parryii,    16    (habits),    91, 
95,  96,  97,  98,  99,  100,  104,  105. 

Spermophilus,  91. 
parvidens,  Citellus  mexicanus,  119,  121. 

Spermophilus  mexicanus,  121. 
parvulus,    Citellus   beecheyi,    150,    155, 

156,  158,  159,  160. 
parvus,   CiteUus  tridecemlineatus,   113, 
115,  117. 

Citellus  tridecimlineatus,  117. 

Spermophilus  tridecemlineatus,  117. 
peninsulae,    Ammospermophilus   leucu- 
rus,  176. 

Citellus  leucurus,  166,  176, 178,  179. 

Tamias  leucurus,  176. 
pennipes,  Ammospernaophilus  leucurus, 
175. 

Citellus  leucurus,  175. 
perotensis,  CiteUus,  21,  41,  42,  132. 

Spermophilus,  132. 
perpallidus,     Callospermophilus    chryso- 

deirus,  206,  207. 
pessimus,  Citellus  mollus,  65. 
phaeognatha,  Arctomys,  55. 

Arctomys  parryi,  91. 
Plague,  bubonic,  10,  11,  13,  16,  26. 
plesius,  CiteUus,  97. 

Citellus  parryii,  16,  17,  86,  87,  88, 
92,  97,  99,  100,  105,  133. 

Spermophilus,  17,  18. 

Spermophilus  empetra,  97. 
Pocket  gopher,  11. 
Poliocitellus,  39,  42,  133. 

franklinii,  43,  44. 
poliopus,  Sciurus,  49. 
Prairie  dog,  35,  36,  38,  55,  88. 
pratensis,  Citellus  spilosoma,  128,  130. 

Spermophilus  spilosoma,  128. 
Protospermophilus  quatalensis,  214,  215. 
Pygmy  squirrel,  51,  52. 

quatalensis,  Citellus,  214,  215. 
Protospermophilus,  214,  215. 

Red  squirrel,  51. 
richardsoni,  Citellus,  73. 

Spermophilus,  62. 
richardsonii,  Arctomys,  73. 

CiteUus,  54,  85. 

Citellus  richardsonii,  5,  8  (habits') 
73,  76,  77,  78,  79,  81,  86. 

Colobotis,  54. 

Spermophilus,  56,  73. 
richmondi,  Sciurus,  51. 
ridgwayi,  Citellus,  215. 
Rock  squirrel,  5,  22  (habits),  35,  39,  43, 
53. 

black-backed,  141. 

brown-headed,  138. 

Couch's,  139. 

Lower  California,  161. 

Malpais,  145. 

Mexican,  55,  136. 

Say's,  23,  142. 

Utah,  4,  146. 

See  also  Antelope  squirrel,  Ground 
squirrel. 


254 


NORTH  AMERICAN  FAUNA 


[No.  66 


Rocky  Mountain  spotted  fever,  16. 
ruficaudus,  Citellus  columbianus,  88,  89. 
rupestris,  Citellus  grammurus,  138. 

Citellus  variegatus,   137,   138,   140, 
141,  144. 

Otospermophilus  grammurus,   138. 
rupinarum,  Citellus  beecheyi,  159. 

saturatus,    Callospermophilus   lateralis, 
212. 

Citellus,  191,  203,  212. 

Citellus  lateralis,  212. 

Spermophilus  lateralis,  212, 

Tamias  lateralis,  212. 
saxicola,  Ammospermophilus  harrisii,  169. 

Citellus  harrisi,  169. 

Citellus  harrisii,  169. 

Spermophilus  harrisi,  169. 
saxicolus,  Spermophilus  harrisii,  169. 
Sciuridae,  classification,  34. 
Sciurus,  34,  35,  48. 

aberti,  49,  50. 

adolphei,  49. 

aestuans,  50. 

alfari,  51. 

alleni,  50. 

apache,  50. 

arizonensis,  50. 

asiaticus,  47. 

aureogaster,  49. 

boothiae,  49. 

buccaius,  136. 

carolinensis,  48,  49,  50,  51, 

coUiaei,  49. 

concolor,  50. 

deppei,  49. 

durangi,  50, 

gerrardi,  51. 

goldmani,  49. 

grammurus,  43,  53,  142. 

griseoiiavus,  49, 

griseus,  49,  50. 

guerlinguetus,  50. 

hoffmanni,  51. 

hudsonicus,  51. 

hypopyrrhus,  48,  49. 

kaibabensis,  50, 

lateralis,  45,  53,  191. 

managuensis,  49, 

mexicanus,  41,  53,  119. 

nayaritensis,  50. 

nelsoni,  49. 

niger,  50. 

oculatus,  50. 

poliopus,  49. 

richmondi,  51. 

sinaloensis,  49. 

socialis,  49, 

striatus,  46. 

thomasi,  49. 

tridecemlineatus,  41,  53,  55,  107. 

truei,  49, 

variegatoides,  49. 

variegatus,  136,  137. 

vulgaris,  48,  49,  50. 

yucatanensis,  49. 
septentrionalis,  Microsciurus,  51. 
Seton,  Ernest  Thompson,  2. 


sierrae,  Citellus  beecheyi,  153,  155. 
sinaloensis,  Sciurus,  49. 
socialis,  Cynomys,  38. 

Sciurus,  49. 
sonomae,  Eutamias  townsendii,  48. 
sonoriensis,  Spermophilus,  187,  188. 
Spermatophilus,  53. 
Spermophila,-  53. 
Spermophiie,  eared,  43. 

Parry's,  55,  56. 

round-tailed,  55. 
Spermophilis,  53. 
Spermophillus,  53. 
Spermophilus,  53. 

alleni,  114. 

annectens,  128. 

annulatus,  44,  55,  16b. 

arens,  125. 

armatus,  55,  56,  78. 

atricapillus,  161. 

hadius,  110,  111, 

harrowensis,  95, 

beecheyi,  148. 

beldingi,  56,  81. 

beringensi$,  95. 

bernardinus,  209, 

brevicaudus,  209. 

buckleyi,  55,  141, 

canescens,  125, 

canus,  67, 

castanurus,  201. 

chrysodeirus,  203. 

cinerascens,  198. 

cinnamomeus,  174. 

columbianus,  85. 

concha,  55,  139. 

cryptospilotus,  130, 

douglasii,  150, 

douglassi,  150. 

elegans,  55,  56,  62,  76. 

em,petra,  56,  91. 

erythroglutaeus,  85, 

erythrogluteia.  85, 

eversmanni,  53. 

fisheri,  154, 

franklini,  133. 

franklinii,  133. 

fulvus,  53,  54. 

goldmani,  164. 

grammurus,  142. 

gunnisoniy  38. 

guttatus,  62. 

harrisii,  55,  56,  167,  170. 

interpres,  180. 

kodiacensis,  56,  103. 

lateralis,  56,  191. 

leucurus,  53,  54,  170. 

macrospilotus,  125. 

macrourus,  55,  136. 

major,  126, 

marginatus,  126,  127. 

mexicanus,  119. 

microspilotus,  125. 

mohavensis,  45,  53,  54,  183. 

mollis,  55,  62,  63, 

neglectus,  187. 

nelsoni,  182, 

obsidianus,  128, 


1938] 


REVISION  OF  THE  GROUND  SQUIRRELS 


255 


Spermophilus — Continued. 

obsoletus,  55,  130. 

olivaceus,  112,  113. 

oregonus,  83. 

osgoodi,  104. 

pallidus,  56,  112. 

parryi,  91. 

parryii,  91. 

parvidens,  121. 

parvus,  117. 

peroiensis,  132. 

plesius,  17,  18,  97. 

pratensis,  128. 

richardsoni,  62. 

richardsonii,  56,  73. 

saturatus,  212. 

saxicola,  169. 

saxicolus,  169. 

sonoriensis,  187,  188. 

spilosomd,  122. 

stephensi,  63,  64. 

tereticaudus,  55,  185. 

texensis,  110. 

townsendi,  65,  76. 

fownsendii,  56,  60,  69,  76. 

tridecemlineatus,  107. 

variegatus,  136. 

wortmani,  195. 

yakimensis,  60. 
spilosoma,  Citellus,  5,  20  (habits),  31, 
41,  42,  55,  70,  120. 

Citellus  spilosoma,   122,   124,   126, 
131,  132. 

Spermophilus,  122. 
Squirrel,  Abert's,  34. 

flying,  35,  52. 

fox,  34,  50. 

gray,  34. 

pygmy,  51,  52. 

red,  51. 

tree,  34,  35,  36,  39,  42,  48,  164. 

(See  aZso  Antelope  squirrel.  Ground 
squirrel,  Rock  squirrel, 
stejnegeri,  Citellus,  3. 
stephensi,  Spermophilus  mollis,  63,  64. 
stonei,  Citellus,  98,  100. 
striatus,  Tamias,  46. 

Sciurus,  46. 
Syntheosciurus,  35,  52. 

brochus,  52. 

Tamias,  35,  46,  47,  56. 

chrysodeirus,  203. 

castanurus,  201. 

cinerascens,  198. 

cinnamomeus,  174. 

harrisi,  167,  170. 

inierpres,  180. 

lateralis,  192. 

leucurus,  44,  170. 

merriami,  47. 

peninsulae,  176. 

saturatus,  212. 

striatus,  46. 

wortmani,  195. 
Tamiasciurus,  34,  35,  51. 

hudsonicus,  50. 
taylori,  Citellus,  216. 


tereticaudus,  Anisonyx,  187. 

Citellus,  30  (habits),  41,  45,  184. 
Citellus     tereticaudus,     185,     187, 

189,  190. 
Ictidomys,  187. 
Spermophilus,  55,  185. 
tersus,     Ammospermophilus     leucurus, 
173. 

Citellus  leucurus,  173. 
tescorum,    Callospermophilus    lateralis, 
199. 

Citellus    lateralis,    198,    199,    206, 
212,  213. 
texensis,  CiteUus  tridecemlineatus,  107, 
109,110,111,122. 
Spermophilus  tridecemlineatus,  110. 
thomasi,  Sciurus,  49. 
Thomomys,  11. 
Thompson,  Ernest  E.,  2. 
townsendi,  Citellus,  216. 
Spermophilus,  65. 
Spermophilus  richardsoni,  76. 
townsendii,  Citellus,  5  (habits),  55,  69, 
73. 

Citellus  to^\Tisendii,  5,  60,  70,  71. 
Spermophilus,  56,  60,  69,  76. 
trepidus,  Callospermophilus,  206. 
CiteUus,  206. 

CiteUus    lateraUs,    201,    202,    204, 
206,  208. 
tridecemlineata,  Arctomys,  107. 
tridecemlineatus,     Citellus,     3,     5,     18 
(habits),  21,  31,  41,  42,  54,  106,  118, 
216. 

Citellus  tridecemlineatus,  107,  110, 

113,  115,  119. 
Colobotis,  54. 
Sciurus,  41,  53,  55,  107. 
Spermophilus,  107. 
tridecimlineatus,  Citellus,  107. 
trinitatis,     Callospermophilus     chryso- 
deirus, 211. 

Citellus  chrysodeirus,  211. 
Citellus  lateralis,  210,  211. 
truei,  Sciurus,  49. 
tuitus,  CiteUus,  215. 
Tularemia,  6,  26,  27. 
tularosae,  Citellus  grammurus,  145. 
Citellus  variegatus,  145. 
Otospermophilus  grammurus,  145. 
Type  localities,  list  of,  56. 

Urocitellus,  53. 

Utah,  Citellus  grammurus,  146. 

Citellus  variegatus,  144,  146. 

Otospermophilus  grammurus,   146. 

variegatoides,  Sciurus,  49. 
variegatus,  CiteUus,  22  (habits),  54,  55, 
136. 

CiteUus   variegatus,   22,    136,    138, 
140,  146. 

Otospermophilus,  136. 

Sciurus,  136,  137. 

Spermophilus,  136. 
vigilis,  Citellus  canus,  66. 

Citellus  mollis,  66. 

CiteUus  townsendii,  61,  66,  67,  68. 


256 


NORTH  AMERICAN  FAUNA 


vinnulus,  Citellus  leucurus,  170. 
vociferans,  Citellus  tereiicaudus,  185,  186. 
volans,  Mus,  52, 
vulgaris,  Sciurus,  48,  49,  50. 

Washington!,  Citellus,  5,  6,  7,  (habits), 
54,  62,  73,  216. 

Citellus  Washington!,  63,  69,  71,  72, 
106,  107. 
washoensis,  Citellus  mollis,  63,  64. 
Woodchuck,  37. 
wortmani,  CaUospermophilus,  195. 

Callospermophilus  lateralis,  195. 

CiteUus,  195. 

CiteUus  lateralis,  191,  193,  195. 


wortmani — Continued. 
Spermophilus,  195. 
Tamias,  195. 

Xerospermophilus,  5,  39,  45,  53,  54,  183, 

184. 

canescens,  125. 
cryptospilotiis,  130. 
macrospilotus,  125. 

yakimensis,  Citellus  mollis,  60,  63. 

Spermophilus  mollis,  60. 
yucatanensis,  Sciurus,  49. 

Ziesel,  53. 


o 


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UNITED  STATES  DEPARTMENT  OF  THE  INTERIOR 
'Harold  L.  Ickes,  Secretary 

FISH  AND  WILDLIFE  SERVICE 
Ira  N.  Gabrielson,  Director 


North  American  Fauna  57 


ATTWATER'S  PRAIRIE  CHICKEN 

ITS  LIFE  HISTORY  AND 

MANAGEMENT 


BY 

VALGENE  W.  LEHMANN 


UNITED  STATES 

GOVERNMENT  PRINTING  OFFICE 

WASHINGTON  :  1941 


For  sale  by  the  Superintendent  of  Documents,  Washington,  D.  C.    -   -     •     -    Price  40  cents 


i  ir' 


ABSTRACT 

ATTWATER'S  PRAIRIE  CHICKEN,  a  characteristic  bird  of  the  Texas 
coastal  prairie,  is  closely  related  to  the  now  extinct  heath-hen  of 
northeastern  North  America.  Once  abundant  in  an  area  extending  from  the 
coastal  tall -grass  prairies  of  southwestern  Louisiana  and  Texas  west  and  south 
to  near  Port  Isabel,  it  has  decreased  in  numbers  as  man  has  exploited  its 
habitat,  until  now  it  is  threatened  ^vith  the  same  fate  as  that  of  the  heath-hen. 

Important  factors  limiting  the  numbers  of  the  bird  include  excessive  or 
persistent  rainfall  dm-ing  the  nesting  season,  heavy  grazing,  excessive  pasture 
burning,  agricultvu^al  operations,  and  overshooting.  Management  will 
usually  involve  protection  from  excessive  kiUing,  improvement  of  food  and 
cover,  and  control  of  predators  and  of  the  kill  by  hunters.  Responsibility 
for  this  rests  with  the  landowTier. 

Optimum  prairie  chicken  range  apparently  consists  of  well-drained  grass- 
land, with  some  weeds  or  shrubs,  the  cover  varying  in  density  from  light  to 
heavy;  and  with  surface  water  available  in  summer;  diversification  within 
the  grassland  type  is  essential.  In  the  absence  of  ample  refuges  for  the 
species,  probably  all  other  favorable  factors  together  will  fail  to  save 
Attwater's  prairie  chicken  from  extinction. 

This  number  continues  the  series  of  the  North  American  Fauna  issued  by 
the  Bureau  of  Biological  Survey,  of  the  United  States  Department  of  Agri- 
culture, prior  to  its  transfer  and  consolidation  with  the  Bureau  of  Fisheries 
on  June  30,  1940,  to  form  the  Fish  and  Wildlife  Service,  in  the  Department 
of  the  Interior. 


CONTENTS 

Page 

Introduction 1 

Former  distribution  of  prairie  chickens  in  Texas 2 

Differences  between  Attwater's  and  the  other  prairie  chickens 4 

Attwater's  prairie  chicken 4 

Lesser  prairie  chicken 5 

Former  abundance  of  Attwater's  prairie  chickens 6 

Present  distribution  and  numbers 7 

Habits 10 

Courtship  and  mating 10 

Nesting 14 

Growth  and  development  of  young 16 

Brood  size 18 

Juvenile  mortality 19 

Family  disintegration 19 

Annual  increase 20 

Flocking 20 

Seasonal  movements 21 

Spring 21 

Summer 22 

Fall  and  winter 24 

Food 25 

Habitat  requirements 30 

Kind  of  environment  best  suited 30 

Character  and  density  of  vegetation 30 

Topography 30 

Water 31 

Seasons  of  scarcity 31 

Limiting  factors 31 

Natural  factors 32 

Rainfall  during  the  nesting  season _■ 32 

Floods 35 

Drought 35 

Hurricanes 35 

Hail 35 

Local  storms 36 

Disease 36 

Spread  of  woody  vegetation 36 

Predation 37 

Nests 37 

Young 38 

Adults 39 

Review  of  natural  factors 40 

Artificial  factors 40 

Agriculture 40 

Pasture  burning 41 

rn 


IV  CONTENTS 

Limiting  factors — Continued. 

Artificial  factors— Continued.  Page 

Overgrazing 42 

Oil  development 43 

Drainage 43 

Pasture  mowing _ 43 

Mechanical  accidents 44 

Hunting 44 

Management 45 

Protection 45 

Habitat  improvement 46 

Evaluating  conditions 47 

Census  methods 47 

Spring  counts  on  the  courtship  grounds 47 

Rope  count 49 

Car-dog  count 52 

Using  the  census 52 

Spring 53 

Summer 54 

Winter 55 

General  recommendations  for  habitat  control 56 

Predator  control 57 

Harvesting  the  surplus 57 

Restocking 58 

Summary 59 

Literature  cited 62 

Index 65 


ILLUSTRATIONS 


Plate  Facing  page 

1.  Attwater's  prairie  chickens  (Tympanuchus  cupido  attwateri)  on  boom- 

ing ground Frontispiece 

2.  Dense  cordgrass  areas  in  Aransas  County,  Tex 4 

3.  Male  Attwater's  prairie  chicken,  showing  vocal  sacs 10 

4.  Nest  and  eggs  of  Attwater's  prairie  chicken;  Colorado  County,  Tex__         14 

5.  Concealment  of  nests  by  Attwater's  prairie  chicken;  Colorado  County, 

Tex 15 

6.  Chicks  of  Attwater's  prairie  chicken;  Colorado  County,  Tex 16 

7.  Wild  indigo  (Baptisia)  in  a  closely  grazed  pasture;  Austin  County, 

Tex 22 

8.  Diversified  cover — excellent  prairie  chicken  range;  Colorado  County, 

Tex 30 

9.  Medium-heavy  to  heavy  cover — excellent  food-cover  conditions  in  a 

moderately  grazed  pasture;  Colorado  County,  Tex 31 

10.  Shells  of  eggs  at  prairie  chicken  nest  destroyed  by  house  cat;  Colorado 

County,  Tex 38 

11.  Native bluestem  prairie — well  populated  by  prairie  chickens;  Colorado 

County,  Tex 39 

12.  Excellent  unburned  cover  at  right  of  road;  inferior  burned  cover  at 

left;  Colorado  County,  Tex 42 

13.  Rope  counting  of  prairie  chickens  on  Matagorda  Island,  Tex 48 

14.  Fenced  plot  planted  to  hegari;  Wharton  Countj',  Tex 56 

Figure  Page 

1.  Distribution  of  Attwater's  prairie  chickens  in  Texas 3 

2.  Movements  of  a  combined  brood,  Colorado  County,  Tex 23 

3.  Rainfall  conditions  in  May  in  the  range  of  Attwater's  prairie  chicken  in 

Texas Facing  page        34 

4.  Diagram  of  the  rope  count 50 

V 


ATTWATER'S  PRAIRIE  CHICKEN 

By  Valgene  W.  Lehmann 
Collaborator,  Division  of  Wildlife  Research,  Fish  and  Wildlife  Service^ 


INTRODUCTION 

Attwater's  prairie  chicken  {Tympanuchu-s  cupido  aUwateri  Ben- 
dire)  (see  frontispiece),  might  well  be  called  the  heath-hen  of  the 
South.  It  is  so  closely  related  to  the  now  extinct  heath-hen  {T.  c. 
cupido)  of  northeastern  North  America  as  to  be  classified  in  the 
same  species.  Like  the  heath-hen,  Attwater's  prairie  chicken  once 
-inhabited  a  large  area,  its  former  range  including  the  coastal  tall- 
grass  (Andropogon)  prairies  of  southwestern  Louisiana  and  in  Texas 
west  and  south  to  Cameron  County,  near  Port  Isabel.  In  certain 
areas  the  birds  were  abundant.  Old-timers  report  that  the  deep 
booming  courtship  calls  of  the  males  once  reverberated  from  the 
prairies  with  such  force  and  monotony  as  actually  to  pain  sensitive 
eardrums.  The  bird,  however,  is  no  longer  abundant.  It  has  de- 
creased in  numbers  as  man  has  exploited  its  habitat  until  now  it  is 
threatened  with  the  fate  of  the  heath-hen — extinction. 

In  his  "Biological  Survey  of  Texas"  Vernon  Bailey  (1905:  19)' 
places  Attwater's  prairie  chicken  at  the  head  of  the  list  of  breeding 
birds  of  the  Texas  coastal  prairie.  In  addition  to  being  a  character- 
istic bird  of  the  region,  this  prairie  chicken  is  probably  the  most 
popular  species  wherever  found.  Most  people  who  know  it  have  a 
genuine  appreciation  of  its  color  and  charm.  Rare  indeed  is  the 
person  who  finds  no  esthetic  stimulus  in  the  sight  of  a  strutting 
male  on  the  booming  ground,  or  a  brood  of  downy  chicks  on  the  edge 
of  a  short-grass  flat.  Both  ranchmen  and  farmers  highly  appreciate 
the  prairie  cliicken's  appetite  for  grasshoppers,  salt-marsh  cater- 
pillars {Estigmene  dcraea)^  and  the  moths  of  the  cotton  leaf  worm 
{Alabama  argillacea).  Under  proper  conditions  prairie  chicken 
hunting  provides  a  high  type  of  sport,  and  the  flesh  of  the  birds, 
especially  that  of  the  young,  is  highly  esteemed  as  food. 


1  Cooperative  contribution  from  the  Texas  Cooperative  Wildlife  Research  Unit,  estab- 
lished by  the  Agricultural  and  Mechanical  College  of  Texas  ;  the  Texas  Game,  Fish,  and 
Oyster  Commission  ;  the  American  Wildlife  Institute ;  and  the  Fish  and  Wildlife  Service. 

*  Publications  referred  to  parenthetically  by  date  (alone  or  followed  by  colon  and  specific 
page)  are  listed  in  the  Literature  Cited,  p.  62. 


Explanation  of  Fkontispiece 

Attwater's  prairie  chicl^ens   (Tympanuchus  cupido 
attwateri)  on  booming  ground 


2  NORTH   AMERICAN   FAUNA    57,   FISH  AND   WILDLIFE    SERVICE 

The  real  appeal  of  the  prairie  chicken,  however,  lies  in  its  con- 
nection with  the  colorful  and  eventful  early  days  in  Texas.  The 
prairie  hen  summons  memories ;  it  prompts  old-timers  to  recall  when 
the  range  was  free  of  wire  fences  and  oil  derricks,  and  rich  grasses 
grew  waist  high.  Thoughtful  people  deplore  the  passing  of  Att- 
water's  prairie  chicken,  one  of  the  last  landmarks  of  the  prairie  as 
it  used  to  be.  Highly  appropriate  was  the  selection  of  this  bird  as 
a  species  of  major  interest  by  the  Texas  Cooperative  Wildlife  Re- 
search unit.' 

FORMER  DISTRIBUTION  OF  PRAIRIE  CHICKENS  IN  TEXAS 

H.  C.  Oberholser,  in  a  letter  to  the  present  writer,  states  that  in 
his  opinion  prairie  chickens  once  occurred  at  some  time  of  year  on 
most  prairie  areas  in  Texas.  In  the  main  it  appears  that  the  differ- 
ent kinds  of  prairie  chickens  in  the  State  occupied  separate  ranges, 
and  that  mixing  and  intergradation  were  confined  largely  to  marginal 
areas. 

The  principal  former  range  of  the  greater  prairie  chicken  in  Texas, 
as  indicated  by  the  records  of  F.  M.  Bailey  (1927:  130),  Gross  (Bent 
1932:  262),  Strecker  (1927:  321),  and  old  residents  with  whom  the 
writer  has  conferred,  was  northeastern  Texas  southwest  to  the  vicin- 
ity of  Waco.  Likewise,  records  show  that  the  lesser  prairie  chicken 
was  indigenous  to  northwestern  Texas  and  the  high  plains  region 
in  winter  to  about  Bandera  and  westward  through  the  "hill  country" 
to  the  arid  plains  west  of  the  Pecos  River  (Bendire  1892:  355,  and 
others).  Attwater's  prairie  chicken,  it  appears,  was  largely  confined 
to  the  better-drained  prairies  of  western  Louisiana  and  Southeastern 
Texas  (fig.  1,  p.  3). 

According  to  Oberholser  (1938:  190-191)  the  eastern  limit  of  the 
range  of  Attwater's  prairie  chicken  was  in  the  vicinity  of  Abbeville, 


*  So  many  persons  have  assisted  in  the  prairie  chicken  studies  that  it  is  impossible  to 
list  them  all.  General  supervision  of  the  work  was  by  Walter  P.  Taylor,  leader  of  the 
Texas  Cooperative  Wildlife  Research  Unit,  College  Station,  Tex.  Valuable  editorial 
suggestions  were  received  from  W.  B.  Davis,  professor  of  wild  game,  School  of  Agriculture, 
Agricultural  and  Mechanical  College  of  Texas ;  and  from  William  J.  Tucker,  executive 
secretary,  Texas  Game,  Fish,  and  Oyster  Commission.  The  bulk  of  examinations  of  crops, 
gizzards,  and  scats  was  done  by  Clarence  Cottam,  Clarence  F.  Smith,  and  their  associates 
in  the  Section  of  Food  Habits,  Division  of  Wildlife  Research,  Fish  and  Wildlife  Service. 

In  his  field  work  in  1938  the  writer  was  assisted  by  H.  R.  Siegler,  field  biologist  of  the 
Research  Unit.  Many  Colorado  County  landowners  cooperated ;  among  these,  M.  C. 
Shindler,  Emil  Gleuck,  Ed  Koy,  Adolf  Renz,  and  I.  V.  Duncan  deserve  special  mention. 
E.  P.  Haddon,  photographer  of  the  Texas  Commission,  took  some  of  the  photographs  here 
reproduced.  The  assistance  of  the  State  game  wardens  was  indispensable.  Deserving 
of  special  mention  are  T.  S.  Boothe,  Beaumont ;  J.  C.  Gardner,  Hull ;  R.  Z.  Cowart,  Rosen- 
berg ;  Ed  McCloskey,  Victoria ;  C.  D.  Tidwell,  Bay  City ;  G.  P.  Ferguson,  Sinton ;  and 
T.  T.  Waddell,  Eagle  Lake.  Waddell's  contributions  to  the  study  were  outstanding;  he 
gave  most  generously  of  his  time,  records,  and  extensive  experience.  To  him,  and  to  all 
others,  the  writer  is  deeply  grateful. 


ATTWATER'S   PRAIRIE    CHICKEN  3 

Opelousas,  and  Bayou  Teche  in  Louisiana.  There  are  no  authentic 
records  of  the  occurrence  of  any  species  of  prairie  chicken  in  Texas 
south  of  northern  Aransas  County,  except  for  one  bird  reported 
from  near  Brownsville  by  Merrill  (1879:  159-160).  Prairie  chickens 
did  not  occur  near  San  Antonio,  Tex.,  in  1890,  for  Babbitt,  in  Bendire 
(1894:  130)  wrote  as  follows:  "The  prairie  hen  is  not  found  in  the 


Probable    Former    Ranqe. 
Preacnf    Range 


FiGiTBE  1. — Present   tlistribution   of   Attwater's  prairie   chicken  in   Texas   and 
probable   former   range  in   the   coastal   section. 

immediate  vicinity  of  San  Antonio,  Tex.,  but  exists  in  great  numbers 
south  and  southeast  from  here,  all  at  an  average  distance  of  100 
miles.  *  *  *"  Simmons  (1925:  82)  submits  the  records  of  O. 
Brinkman  and  C.  D.  Oldright  as  evidence  that  Attwater's  prairie 
chicken  occurred  as  a  breeding  bird  in  the  vicinity  of  Austin.  Travis 


4         NORTE  AMERICAN  FAUNA   57,   FISH  AND  WILDLIFE    SERVICE 

County,  and  in  Williamson  County  as  late  as  1878,  but  the  accuracy 
of  the  data  is  questionable.  Apparently  the  limit  was  the  northern 
edge  of  the  coastal  prairie, 

Eoughly,  the  territory  occupied  by  Attwater's  prairie  chicken  was 
south  of  a  line  extending  northeast  from  Kefugio  tlirough  Fannin, 
Thomaston,  Provident  City,  Rock  Island,  Industry,  Welcome,  Bell- 
ville,  Prairie  View,  Tom  Ball,  Humble,  Liberty,  Devers,  Cheek,  and 
Orange.  All  this  area  of  approximately  8,500,000  acres  in  coastal 
Texas,  however,  was  not  occupied.  Deciduous  woodlands  near  rivers, 
as  along  the  San  Antonio,  Guadalupe,  Colorado,  Brazos,  and 
Trinity,  were  used  only  to  a  limited  extent  and  only  along  the  mar- 
gins. Prairie  chickens  did  not  occupy  the  pine  forests  in  Harris 
County  and  to  the  east  or  the  thick  mesquite-acacia  brush  that  oc- 
curred in  considerable  stands  in  Calhoim  and  other  western  counties 
as  much  as  100  years  ago.  Brackish  and  salt-water  marshes  in  Or- 
ange, Jefferson,  and  Chambers,  and  less  widely  in  other  counties 
to  the  west,  and  extensive  cordgrass  {Spartina  spartinae)  flats  (pi.  2) 
in  Aransas  County  and  elsewhere  in  low  country  bordering  the  Gulf, 
probably  always  were  little  used  by  chickens  except  to  a  limited 
extent  in  winter.  There  were,  however,  about  6,000,000  acres  of 
bluestem  prairie  that  probably  supported  many  prairie  chickens  in 
favorable  years. 

DIFFERENCES  BETWEEN  ATTWATER'S  AND  THE  OTHER  PRAIRIE 

CHICKENS 

During  the  nineteenth  century  three  kinds  of  prairie  chickens  oc- 
curred in  Texas:  the  greater  prairie  chicken  {Tympanuchus  cupido 
americanus  Reichenbach),  Attwater's  prairie  chicken  {T.  c.  attwateri 
Bendire),  and  the  lesser  prairie  chicken  {T.  pallidicinctus  Ridg- 
way).  Differences  between  the  greater  and  Attwater's  prairie  chick- 
ens are  slight;  the  lesser  prairie  chicken  is  somewhat  better 
characterized. 

ATTWATER'S  PRAIRIE  CHICKEN 

Bendire   (1894:  130)   described  Attwater's  prairie  chicken  as — 

Smaller  than  T.  americanus  [greater  prairie  chicken],  darker  in  color,  more 
tawny  above,  usually  with  more  pronounced  chestnut  on  the  neck ;  smaller 
and  more  tawny  light  colored  spots  on  the  wing  coverts,  and  much  more 
scantily  feathered  tarsus,  the  latter  never  feathered  down  to  the  base  of 
toes,  even  in  front ;  a  broad  posterior  strip  of  bare  skin  being  always  ex]X)sed, 
even  in  winter,  while  in  summer  much  of  the  greater  part  of  the  tarsus  is 
naked. 

In  weight  Attwater's  prairie  chicken,  however,  is  not  perceptibly 
lighter  than  the  greater  prairie  chicken.  The  average  of  10  males 
(33.11  ounces,  as  shown  in  table  1,  p.  5)  exceeded  by  2.11  ounces 
the  average  weight  of  the  greater  prairie  chicken   (31  ounces),  as 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


Plate  2 


c3 

•< 

a 

^ 

!C 

<u 

4-^ 

t/3 

03 

3 

-*J 

<; 

-tJ 

<*-c 

< 

o 

>> 

Oi 

jD 

01 

& 

t3 

a> 

CO 

o 

O 

c3 

Lh 

03 

bD 

CS 

■a 

ATTWATER'S   PRAIRIE    CHICKEN 


given  by  Gross  (1930a:  40).  The  average  weight  of  six  females 
(25.7  ounces)  was  only  0.6  ounce  less  than  that  of  the  female  greater 
prairie  chicken  (26.3  ounces),  according  to  the  same  authority  (loc. 
cit.).  The  weight  of  Attwater's  prairie  chickens,  especially  that  of 
males,  varies  perceptibly  from  season  to  season ;  three  males  obtained 
at  the  beginning  of  the  courtship  season  were  appreciably  heavier 
(about  7.5  ounces)  than  those  collected  at  other  times.  Darkness  of 
color,  tawniness  above,  and  the  amount  of  chestnut  on  the  neck  are 
other  characters  that  vary  greatly  both  seasonally  and  individually. 
Winter  specimens  are  generally  lighter  in  color  than  those  collected 
in  spring;  they  have  comparatively  little  chestnut  on  necks  and 
backs.  The  feathering  on  the  tarsus  also  varies  with  the  season ;  the 
legs  of  specimens  collected  in  winter  are  well  feathered  to  the  base 
of  the  toes.  The  style  of  barring  on  the  back  and  rump,  according 
to  F.  M.  Bailey  (1927:  130),  is  the  same  for  both  subspecies,  that  is, 
the  bars  are  single,  broad,  and  solid  black.  Altogether,  physical 
differences  between  Attwater's  and  the  greater  prairie  chicken  are 
minor  and  insufficient  to  allow  accurate  field  identification.  In  a 
series  of  skins,  however,  the  smaller  measurements  of  wing,  tail,  bill, 
and  total  length  and  the  differences  in  general  ruddiness  and  buffiness 
of  the  underparts  are  characteristic  and  serve  to  separate  Attwater's 
prairie  chicken  as  a  subspecies. 

Table  1. — Weights  of  16  AUwatefs  prairie  chickens 


County 

Date  collected 

Weight  1 

County 

Date  collected 

Weight  I 

Grams 

Ounces 

Grams 

Ounces 

MALES 

Colorado 

Do 

Apr.  17,  1939  > 
Sept.   1,1937  3 
Sept.  4.1937  3 
Oct.    23,1937 
Nov.    3,1937 

Jan.      6, 1938 
Jan.    27,1938 
Feb.   14,1938 

1, 135.  20 
682.  00 
590. 07 
760.  20 
874. 00 

723. 69 
715.  24 
726.80 

40.03 
24.05 
20.  SI 
26.81 
30.82 

25.18 
25.22 
25.63 

MALES 

Eefugio 

Do 

Colorado.. 

Austin__ 

Colorado..- 

FEMALES 

Refugio... 

Colorado 

Do 

Feb.  15,1938 

do 

Mar.  18, 1938 
Apr.   10, 1938* 
July    26,1938 

Feb.   15,1938 
Aug.  20,1938 
Aug.  23,1938 

1, 103.  70 
1, 125.  20 
1, 120.  45 
1, 077.  26 
921.  34 

785.  60 
722.  89 
708.  72 

38.92 
39  68 

Do 

Do 

39.51 
38  00 

Do 

32  50 

FEMALES 

Colorado 

Do 

27.70 
25  50 

Austin 

25.00 

•  Average  weights:  Males, ! 
'  Taken  from  hawk. 

'  Immature  bird. 

*  Taken  from  poacher. 


3.94  gm.  (33.11  oz.);  females,  730.49  gm.  (25.  70  oz.). 


LESSER  PRAIRIE  CHICKEN 


The  lesser  prairie  chicken  is  somewhat  smaller  than  either  of  its 
relatives.  Verne  E.  Davison,  in  a  letter,  reports  that  20  mature  males 
from  Oklahoma  weighed  23.50  to  31.50  ounces  and  averaged  27.56 
ounces.  Five  hens  weighed  23.75  to  27.50  ounces  and  averaged 
25.55  ounces.  In  other  words,  these  male  lesser  prairie  chickens  were, 
on  the  average,  3.44  ounces  lighter  than  the  male  greater  prairie 
chickens  (31  ounces)  weighed  by  Gross  (1930a:  40);  these  female 


6         NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

lesser  prairie  chickens  weighed  0.55  ounces  less  than  the  female 
greater  prairie  chickens  that  Gross  obtained.  According  to  Bailey 
(1927:  131),  the  general  coloration  of  the  lesser  prairie  chicken  is 
paler  than  that  of  either  the  greater  or  Attwater's,  and  the  color 
and  arrangement  of  the  bars  on  back  and  neck  also  differ.  Whereas 
the  bars  are  single,  broad,  and  solid  black  in  both  the  greater  and 
Attwater's  forms,  they  are  treble,  a  broad  brown  bar  enclosed  by 
two  narrow  black  ones,  in  the  lesser  species. 

FORMER  ABUNDANCE  OF  ATTWATER'S  PRAIRIE  CHICKEN 

Accurate  information  as  to  the  former  abundance  of  Attwater's 
prairie  chicken  is  difficult  to  obtain,  although  the  data  at  hand 
record  their  numbers  in  certain  areas.  Many  old  cattlemen  of  the 
coastal  prairie  have  told  the  writer  that  in  early  days  the  prairie 
chickens  were  relied  upon  to  furnish  fresh  meat  for  the  cattle  camps. 
The  task  of  killing  40  or  50  prairie  chickens  was  menial,  the  cook  of 
the  outfit  usually  attending  to  it. 

In  the  Eagle  Lake  area,  Colorado  County,  not  more  than  35  years 
ago,  prairie  chickens  were  shot  as  clay  pigeons  are  today.  On  ap- 
pointed occasions  parties  of  10  to  20  or  more  men  encamped  in  the 
sandhill  country  along  the  Bernard  River  and  hunted  the  birds  for 
periods  varying  from  a  few  days  to  a  week  or  more.  At  the  end 
of  each  day  the  chickens  killed,  or  their  heads,  were  tallied.  At  the 
end  of  the  encampment  period  the  party  having  killed  the  smallest 
number  paid  the  expenses  of  the  outing.  Waddell  and  others  state 
that  10  or  more  piles  of  prairie  chickens,  each  containing  upwards 
of  100  birds,  usually  were  left  at  the  camp  sites  to  rot  or  to  be  eaten 
by  vultures.  These  encampments  began  about  July  4  and  continued 
through  fall  and  winter. 

During  the  summer  of  1893  or  1894,  in  Matagorda  County,  near 
Bay  City,  V.  L.  LeTulle  reports  that  71  Attwater's  prairie  chickens 
were  shot  in  2  hours;  and  that  in  1895,  at  the  site  of  the  present  town 
of  Van  Vleck,  he  and  3  friends  killed  72  birds  in  an  afternoon,  and 
except  for  poor  marksmanship  would  have  bagged  many  more. 
Near  Wharton,  in  Wharton  County,  in  the  fall  of  1894  or  1895, 
LeTulle  found  340  piled  where  hunters  had  camped. 

Mendell  Burrell  of  the  Ray  Pipkin  ranch  (Big  Hill  country, 
Jefferson  County)  told  the  writer  that  as  late  as  1920  his  domestic 
chickens  were  fed  under  the  ranch  house  in  winter  to  prevent  prairie 
chickens  from  consuming  the  grain.  In  the  same  area  it  is  said  that 
flocks  of  from  150  to  200  Attwater's  prairie  chickens  often  alighted 
in  the  introduced  chinaberry  trees  {Melia  azedarach  imibraculifera) 
around  the  ranch  houses  and  fed  extensively  on  the  berries.  In 
verification  of  this  statement  W.  S.  Boothe,  State  game  warden  at 


ATTWATER'S   PRAIRIE    CHICKEN  7 

Beaumont,  Tex.,  presented  the  writer  with  a  photograph,  taken  in 
1910  on  the  Wliite  Ranch  at  Devers,  showing  a  dozen  prairie  chickens 
in  a  chinaberry  tree  beside  a  house. 

C.  H.  Brosig,  who  hunted  Attwater's  prairie  chickens  in  the  Eagle 
Lake  area  for  more  than  40  years,  reported  that  the  birds  once 
were  so  numerous  in  the  sandhill  country  bordering  the  Bernard 
River  that  a  new  covey  frequently  was  flushed  while  singles  from 
one  previously  discovered  were  being  pursued.  Paul  Mundelius  noted 
a  similar  high  density  in  concentrations  of  prairie  chicken^  in  the 
Sealy-San  Felipe  section  in  the  eastern  part  of  Austin  County  in 
1873-75.  These  conditions  are  seldom  found  on  areas  where  the  pop- 
ulation is  less  than  one  bird  to  an  acre,  and  they  show  the  former 
abundance  of  Attwater's  prairie  chickens  in  favorable  areas.  Not 
all  the  coastal  bluestem  {Andropogon)  prairie,  about  6,000,000  acres, 
wa3  equally  favorable  for  prairie  chickens  even  under  pristine  con- 
ditions; well-drained,  well-populated  country  (one  bird  to  an  acre), 
as  along  the  Bernard  River,  did  not  aggregate  more  than  900,000 
acres,  or  about  15  percent  of  the  inhabited  range.  A  little  more  than 
half,  3,300,000  acres,  or  55  percent,  of  the  prairie  country  was  only 
fairly  well  drained ;  these  areas,  protected  for  periods  up  to  17  years, 
now  have  a  maximum  population  of  about  one  bird  to  each  10  acres. 
Approximately  1,800,000  acres,  or  30  percent,  was  poorly  drained; 
prohibition  of  hunting  for  periods  up  to  15  years  has  not  produced 
a  population  in  excess  of  one  bird  to  each  50  acres  on  certain  of 
these  large  ranches.  Probably,  therefore,  the  former  abundance  of 
Attwater's  prairie  chicken  in  Texas  approached,  but  seldom  if  ever 
attained  or  exceeded,  1,000,000  individuals,  even  in  peak  years. 

PRESENT  DISTRIBUTION  AND  NUMBERS 

Data  on  the  present  status  of  Attwater's  prairie  chicken  (table  2, 
p.  8)  were  obtained  as  follows: 

At  least  90  percent  of  all  fanns  and  ranches  known  or  thought 
to  have  been  occupied  by  the  birds  in  1937  were  visited  by  the  writer 
in  company  with  local  State  game  wardens.  Unless  the  warden  was 
thoroughly  familiar  with  conditions  on  the  various  areas,  conference^ 
were  held  with  landowners,  managers,  cowboys,  guides,  hunters,  or 
other  persons  who  were  in  position  to  know  the  status  of  prairie 
chickens  on  particular  tracts.  After  the  conferences  a  general  recon- 
naissance of  the  areas  wa^  made  by  automobile  or  on  horseback,  and 
notes  were  taken  on  the  topography,  vegetation,  surface  water,  and 
soil  to  ascertain  the  general  suitability  of  the  land  for  prairie  chickens, 
as  was  done  in  similar  studies  previously  made  in  the  Eagle  Lake  area. 

Then  in  the  light  of  all  available  information  the  range  of  Att- 
water's prairie  chicken  was  mapped  in  each  county,  and  representa- 


8         NORTH  AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

tive  sample  areag  were  selected  for  intensive  study.  The  birds  were 
then  "rope  counted"  *  on  the  sample  tracts.  Finally,  the  total  popu- 
lation of  the  area  was  estimated  from  the  data  obtained  by  counting 
the  sample  plots. 


Table  2. — Population  status  of 

the  Attwater's  prairie  cMckeri  in  Texas 

{1931) 

Size  of 
tract 

Census  area 

Territory  occupied 
per  bird 

Popula- 
tion of 
whole 
tract 

County 

Size 

Popula- 
tion (rope 
count) 

Census 
area 

Whole 
tract 

Acres 

Acres 
1,080 
630 

Number 
56 
106 

Acres 
19.2 
5.0 

Arre^ 

Numhtr 

42,000 

1,610 

162 

9.9 

4,242 

6,554 
5,000 

3  25 

Goliad  1 

34 

11,  554 

Dewitt  • 

f 

230 
873 
218 

4 
14 
0 

57.5 
62.3 

Victoria 



1 

Total  or  average  (3) 

65,  535 

1,321 

18 

73.4 

892 

Wharton  i 

4,000 
4,915 
18, 022 
49,152 

4,200 
14,250 

32 
315 

131.2 
45.2 

76, 089 

18, 450 

347 

53.1 

1,433 

736 

0 

12,  288 
f 

736 

0 

'50 

542 
364 
219 
157 
716 
482 

4 
0 
1 
3 
0 
0 

135.5 

1 

Harris      _  .  

219.0 
52.3 



I 

Waller              .- -.- 

Fort  Bend 

Total  or  average  (6) 

103, 878 

2,480 

8 

310.0 

335 

f 

585 
248 
269 
334 

29 
2 
1 
2 

20.1 
124,0 
269.0 
167.0 

..  . 

I            -" 

Galveston  ' -__ 

Total  or  average  (7) 

54,  067 

1,436 

34 

42.2 

1,281 

Jefferson      -  

4,000 
700 
400 

24 
1 
0 

166.6 
700.0 

Ohamhers 

Liberty                         --            - 

Total  or  average  (8) 

91,  724 

5,100 

26 

204.0 

449 

Grand  total  or  average 

457, 135 

31, 133 

594 

52.4 

8,711 

1  Counties  in  which  prairie  chickens  occur  but  in  which  counts  were  not  made  because  of  scarcity  of  birds 
or  similarity  of  the  areas  to  adjoining  counties. 

2  Numbers  in  parentheses  in  total  lines  refer  to  areas  correspondingly  numbered  in  the  map,  fig.  1,  p.  3. 
'  Estimates  supplied  by  game  wardens. 


*  For  an  account  of  the  method  used  in  rope  counting  see  p.  49. 


ATTWATER'S   PRAIRIE    CHICKEN  9 

The  known  range  of  Attwater's  prairie  chicken  in  Texas,  as  of 
September  1937,  aggregated  only  457,135  acres,  as  compared  with 
approximately  6,000,000  acres  in  former  times.  The  range  has  there- 
fore been  reduced  more  than  93  percent  during  the  past  100  years  or  so. 
The  birds  are  still  to  be  found  in  the  counties  of  Aransas,  Kefugio, 
Goliad,  Victoria,  Calhoun,  Dewitt,  Jefferson,  Waller,  Galveston, 
Chambers,  Liberty,  Lavaca,  Wharton,  Colorado,  Matagorda,  Austin, 
Fort  Bend,  Harris,  Brazoria,  and  possibly  Jackson  and  Orange, 
although  they  have  not  been  reported  by  reliable  observers  in  the 
last  two  for  several  years.  They  have  definitely  been  extirpated 
from  Willacy  and  Montgomery  Counties,  and  their  distribution  has 
become  restricted  throughout  the  State,  especially  in  the  counties 
of  Goliad,  DeWitt,  Lavaca,  Calhoun,  Matagorda,  Galveston,  Fort 
Bend,  Liberty,  Jackson,  and  Orange,  if  they  occur  there  at  all. 
Prairie  chickens  had  not  been  seen  in  Goliad  County  for  at  least 
10  years  prior  to  1937,  at  which  time  four  birds  were  reported  on 
the  W.  J.  O'Conner  ranch. 

No  more  than  half  the  grassland  range  in  any  county  except 
Refugio  is  occupied  by  prairie  chickens.  In  the  counties  of  Mata- 
gorda, Lavaca,  Wharton,  Calhoun,  Liberty,  Jackson,  and  Fort  Bend 
even  less  than  10  percent  of  apparently  satisfactory  pasture  is  inhab- 
ited. Roughly,  the  available  range  for  prairie  chickens  is  only  about 
30  percent  occupied  and,  with  the  exception  of  about  20,000  acres 
in  southeastern  Refugio  County,  all  the  occupied  area  has  a  sparse 
population. 

The  total  number  of  prairie  chickens  in  coastal  Texas  in  the 
summer  of  1937  was  only  about  8,700.  The  estimated  1937  popula- 
tion was  probably  less  than  1  percent  of  the  number  believed  to 
have  occupied  the  coastal  prairie  in  peak  years  before  it  was  devel- 
oped by  white  men.  Approximately  4,200  chickens  (or  almost  50 
percent  of  the  known  population  of  the  State)  inhabit  two  ranches 
in  Refugio  and  Aransas  Counties.  The  estimated  population  of 
4,500  birds  for  the  remainder  of  Texas  is  small  indeed  ! 

The  consensus  is  that,  during  the  past  10  years,  the  number  of 
prairie  chickens  has  decreased  in  all  coastal  counties  except  Refugio 
and  Brazoria.  In  Refugio  County  there  has  been  a  rapid  increase 
in  recent  years,  probably  largely  because  of  excellent  protection  on  the 
Salt  Creek  and  Martin  O'Conner  ranches.  Since  1935  the  birds  have 
spread  from  these  onto  the  O'Brien,  Powers,  Welder,  and  Heard 
ranches  near  Greta,  Refugio  County,  and  probably  also  into  Goliad 
County.  Because  of  protection  during  a  5-year  close  season  in 
Brazoria  County  (1932-36),  R.  Z.  Cowart,  State  game  warden  there 
believes  that  in  1937  the  number  of  birds  had  reached  and  possibly 
slightly  exceeded  the  1927  population  level. 


10       NORTH  AMERICAN   FAUNA    5  7,    FISH  AND   WILDLIFE    SERVICE 

The  prairie  chicken  population  of  the  counties  of  Orange,  Liberty, 
Fort  Bend,  Matagorda,  Jackson,  Lavaca,  Calhoun,  and  Goliad,  where 
populations  of  less  than  100  birds  per  county  obtain,  may  already  be 
reduced  to  the  point  where  recovery  will  be  extremely  difficult  or 
even  impossible.  So  long  as  any  birds  remain,  however,  every  effort 
should  be  made  to  build  up  their  numbers. 

HABITS 

COURTSHIP  AND  MATING 

Prairie  chickens  do  not  pair  for  breeding,  but  are  promiscuous. 
Males  occupy  selected  courtship  stations  on  booming  grounds  (see 
frontispiece) ,  which  are  visited  by  the  females.  Copulation  may  take 
place  elsewhere,  however,  in  case  of  chance  meetings.  To  attract  the 
females,  the  cocks  put  on  elaborate  exhibitions,  and  their  courtship 
antics  are  unbelievably  weird.  Of  special  interest  is  the  manner 
in  which  the  booming  call  is  rendered. 

This  call  of  the  male  resembles  somewhat  the  sound  whur-ru-rrr^ 
with  strong  accent  on  the  second  syllable.  Although  it  generally 
lasts  about  6  seconds,  the  call  varies  in  length  and  tone.  In  mid- 
season  the  calls  are  characteristically  deep  and  full-throated;  later 
they  become  shorter  and  higher  pitched,  possibly  because  the  males 
are  then  less  vigorous.  The  sound  of  the  booming  carries  for  a 
mile  or  more  on  quiet  days.  It  has  a  ventriloquial  effect  and  often 
seems  farther  away  or  closer  than  it  actually  is.  During  the  court- 
ship season  males  boom  regularly  in  early  morning  (sunrise  until 
about  8  a.  m.)  and  in  late  afternoon  (5:30  p.  m.  until  sunset),  but 
calls  have  been  heard  at  all  hours  of  the  day  and  night.  Booming 
at  night  is  sporadic,  however,  even  during  the  peak  of  the  courtship 
season  in  March,  being  most  common  when  the  moon  is  bright  and 
when  there  is  little  wind. 

The  appearance  of  the  male,  while  booming,  is  striking.  As  a 
preliminary  to  uttering  the  call  he  stretches  his  neck  forward  par- 
allel to  the  ground.  The  erected  pinnae,  or  neck  tufts,  point  for- 
ward; the  spread  tail  is  held  vertically  or  even  inclined  slightly 
over  the  back.  The  wings  are  extended  downward  and  held  firmly 
against  the  body  and  legs,  the  primaries  almost  touching  the  ground. 
The  whole  body  appears  strained  and  rigid.  A  short  run  forward  is 
followed  by  vigorous  stamping  with  the  feet,  which  lasts  only  a  few 
moments,  but  which  under  favorable  conditions  is  distinctly  audible 
for  50  feet  or  more.  Inflation  of  the  air  sacs,  which  are  actually 
but  one  sac  with  two  lateral  portions  (pi.  3)  is  synchronized  with 
the  stamping.  The  first  syllable  of  the  booming  is  given  before 
stamping  ends,  the  male  quickly  jerking  his  head  downward  as  he 
begins  the  call  and  keeping  it  there  until  the  air  sac  is  deflated. 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


Plate  3 


Male  Attwater's  prairie  chicken,  showing  vocal  sacs.      (Photo  from  Texas  Game, 
Fish,  and  Oyster  Commission.) 


ATTWATER'S    PRAIRIE    CHICKEN  11 

The  call  of  Attwater's  prairie  chicken  apparently  is  given  in  the 
same  manner  as  was  that  of  the  extinct  heath-hen,  its  near  relative. 
Gross  (Bent  1932:  272)  describes  the  booming  mechanism  of  the 
heath-hen  as  follows : 

The  sacs  do  not  produce  the  notes,  as  was  thought  by  some  of  the  earlier 
ornithologists,  but  have  much  to  do  with  modifying  the  sounds  produced  by 
the  syrinx  (the  vocal  mechanism  at  the  juncture  of  the  bronchial  tubes).  The 
sounds  are  produced  by  the  air  forced  from  the  lungs,  which  vibrate  specialized 
membranes  of  the  syrinx  under  control  of  a  complex  set  of  muscles.  The 
sound  waves  then  issue  through  the  trachea  and  glottis  to  the  pharynx.  In 
the  production  of  such  notes  as  the  ordinary  cackle  the  mandibles  are  opened 
and  the  air  accompanied  by  the  sound  waves  issues  out  of  the  mouth.  In  the 
tooting  [booming]  performance  the  mandibles  are  tightly  closed,  the  throat 
patch  is  elevated,  and  the  tongue  is  forced  against  the  roof  of  the  mouth 
(palate)  by  the  mylohyoides  muscles,  which  close  off  the  exit  through  the 
Internal  nares.  The  tongue  is  bent  in  such  a  way  that  it  causes  the  glottis  at 
the  base  of  the  tongue  to  open  directly  in  front  of  the  esophagus.  The  air 
now  coming  from  the  respiratory  system  is  forced  to  fill  the  modified  anterior 
end  of  the  esophagus,  or  gullet,  which  becomes  distended  like  a  balloon.  While 
the  air  sac  is  filling,  the  sound  waves  produced  by  the  syrinx  beat  against 
these  tense  drumlike  membranes,  which  serve  as  resonators  for  the  sounds 
and  give  them  their  great  carrying  power. 

The  booming  call  does  not  complete  the  vocabulary  of  male  prairie 
chickens  at  courtship  time.  The  rendition  of  additional  calls,  all 
distinctly  henlike,  is  described  as  closely  as  possible  on  p.  12.  On 
windy  days  cackling  sounds,  like  Nos.  1,  2,  and  3  in  the  list,  carry 
farther  than  booming.  The  call  note  picoik  (No.  14)  dominates 
when  hens  visit  the  courtship  grounds.  Observers  may  identify 
grounds  where  females  are  present  by  this  piooik  call. 

Males  do  not  confine  their  courtship  activities  to  vocalizing,  and 
fights  are  common.  Opponents  usually  approach  each  other,  utter- 
ing peculiar  whining  notes,  with  necks  outstretched,  ear  tufts  erected, 
tails  spread,  wings  drooped,  and  air  sacs  deflated.  Then,  as  if  pos- 
sessed of  the  same  thought,  they  suddenly  hop  off  the  ground,  wings 
beating  rapidly,  and  clash  in  midair.  These  bouts  are  usually  dis- 
continued after  three  or  four  flurries,  and  the  victors  seem  satisfied 
after  pursuing  their  opponents  for  short  distances.  Many  feathers 
are  frequently  lost,  but  fights  seldom  if  ever  end  fatally.  Males 
sometimes  engage  fancied  opponents,  as  clumps  of  weeds  or  tufts 
of  tall  grass,  and  at  other  times  they  joust  and  bluff  for  periods  up 
to  30  minutes  or  more  without  striking  a  blow.  With  necks  out- 
stretched, heads  held  a  few  inches  apart,  and  wings  dangling  loosely, 
they  resemble  domestic  roosters  fighting.  At  intervals  males  flutter 
into  the  air  to  heights  of  3  to  5  feet,  alighting  nearly  on  the  spot 
whence  they  arose.     Their  surplus  energy  apparently  must  be  expended 

303807°— 41 2 


12       NORTH  AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

in  one  way  or  another,  although  activity  sometimes  lags  for  brief 
periods. 

CALL    OF    MALE    PRAIRIH    CHICKENS    ON    COURTSHIP    GEOTJHDS 

1.  Ca-ca'-ca-ca-ca-ca-ca-cor-caa-ccui—.  All  except  last  two  notes  given  rapidly. 

2.  Ca-ca'-caa,   ca-ca'-caa Rapid. 

3.  Ca-ca-ca-ca'-ca Rapid,  accent  on  second  to  last  syllable. 

4.  Ca-ca-ca-corkeeee All  except  last  syllable  given  rapidly. 

5.  Ktmeee,   ca-ca-ca-oa-ca-ca First  syllable  drawn  out^  remainder  given 

rapidly. 

6.  Kwerr-hwerr-pwah First  two  syllables  drawn  out. 

7.  Ewier-kwier-kicier-kivier All  syllables  drawn  out. 

8.  Pwark  or  pwarrk Medium    rapid.     Often    preceeds    cackling 

or  booming,  carries  as  far  as  or  farther 
than  booming  notes  under  certain 
weather  conditions. 

9.  Caaa-caaa-caaa-caaaa Slow  and  drawn  out.     Sounds  almost  ex- 

actly like  protests  of  a  domestic  setting 
hen  that  is  disturbed. 

10.  Piviek,  pioark Medium  rapid. 

11.  Piviek,   pwiek,  pwiek All    notes    drawn    out   with    emphasis    on 

the  iek. 

12.  Pioiek,   ca-ca-ca-ca-ca-caa Pause  after  first  note,  cackle  given  rapidly. 

13.  Pivk-pivk-pwk-pwk-pick-pwk Harsh    notes    executed   rapidly,    but   in    a 

subdued  tone. 

14.  Pwoik,  pwoik,  pwoik,  pwoik Executed   rapidly    and   with   much   vigor. 

These  notes  predominate  all  other  calls 
when  a  female  approaches  a  courtship 
ground. 

15.  Kliee,  kliee,   kliee;  corca-ca-ca—  Kliee's  drawn  out ;  ca's  given  rapidly.    This 

is  a  prominent  call  in  early  spring. 

16.  Kwoo,  kivoo;  kwah,  kivah Rapid.     Another    prominent    early    season 

call. 

The  performers  do  considerable  feeding  when  they  first  arrive  on 
the  courtship  ground,  and  certain  of  them  feed  sporadically  throughout 
their  stay.  At  other  times  individuals,  sometimes  an  entire  group,  sit 
or  stand  in  their  places  and  look  about.  Rest  periods  terminate 
abruptly,  however,  when  a  male  recognizes  a  real  or  fancied  challenge, 
or  when  a  hen  appears. 

While  the  male  is  bold  and  noisy  during  the  mating  season,  the  female 
is  demure  and  shy.  Hens  visit  the  courtship  grounds  irregularly  except 
early  in  March.  Even  in  well-populated  territory  a  week  sometimes 
elapses  before  the  persistent  male  performers  are  rewarded  by  female 
company.  When  on  or  near  a  drumming  ground,  hens  usually  appear 
little  interested  in  the  spirited  antics  of  the  ob\aously  excited  males. 
Sometimes,  however,  they  walk  among  the  contestants  and  mate  with 
one  or  several  of  them.  Hens  usually  remain  at  the  courtship  areas 
briefly;  usually  they  stay  only  a  few  minutes  before  leaving  to  feed 
elsewhere  or  fly  to  the  vicinity  of  their  nests. 


ATTWATER'S   PRAIRIE    CHICKEN  13 

In  Colorado  County  signs  of  the  approaching  breeding  season  w^re 
noted  early  in  January  (1937)  and  late  in  December  (1938)  when  cer- 
tain males,  probably  the  most  vigorous,  pecked  at  and  otherwise  bullied 
their  fellows  as  the  flocks  left  the  roost  or  fed  early  each  morning.  A 
few  weeks  later,  early  in  February  (1937),  and  late  in  January  (1938), 
males  assembled  early  in  the  morning  on  short-grass  areas  that  later 
served  as  courtship  grounds,  and  fought  and  maneuvered  for  choice 
positions.  For  a  week  or  more,  calls  consisted  largely  of  miscellaneous 
squawks  and  cackles,  and  fights,  though  frequent,  were  of  short  dura- 
tion. Males  occasionally  attempted  to  drum  or  boom,  but  their  notes 
lacked  midseason  depth  and  vigor.  Females,  still  in  winter  flocks, 
seemed  indifferent  to  the  proceedings.  It  was  not  until  February  12,  in 
1937,  and  January  26,  in  1938,  that  booming  was  commonly  heard,  and 
each  year,  after  2  to  3  weeks,  flocks  of  females  generally  broke  up  and 
the  courtship  season  was  well  under  way.  During  both  1937  and  1938 
courtship  activity  was  at  its  peak  in  March,  continuing  through  April 
and  ending  on  May  20,  in  1937,  and  on  May  21,  in  1938,  when  the  last 
booming  calls  were  heard. 

Key  areas  during  the  courtship  season  are  the  booming  grounds  where 
males  assemble  each  morning  from  daybreak  until  about  8  a.  m.  and 
each  afternoon  from  5:30  p.  m.  until  dark  and  give  their  courtship 
display. 

The  preferred  booming  ground  is  a  short-grass  flat,  an  acre  or  so  in 
extent,  surrounded  by  an  area  of  medium  to  heavy  grassy  cover  suitable 
for  nesting.  Of  several  hundred  sites  observed  during  3  years  (1936- 
38)  only  one  was  on  ground  elevated  enough  to  be  termed  a  small  knoll. 
The  others  were  even  with  or  slightly  below  the  adjacent  land  surface. 
Stoddard  (Bent  1932:  245),  discussing  the  greater  prairie  chicken  in 
Wisconsin,  says  that  "the  'cooing'  ground  [courtship  ground]  at  the 
sandy  west  end  of  Sauk  Prairie  has  been  used  each  spring  for  over  30 
years,  the  birds  always  using  the  same  knoll  whether  in  rye,  stubble, 
or  grown  to  grass."  Courtship  grounds  of  Attwater's  prairie  chicken 
do  not  show  the  same  degree  of  permanence.  Cultivation  seemingly  re- 
sults in  immediate  eviction,  whether  the  crop  is  rice,  corn,  cotton,  or 
something  else.  Likewise,  the  birds  do  not  use  fallow  fields  except  where 
cultivated  land  is  the  only  other  environmental  type  available,  or  where 
the  fallow  land  has  aged  to  the  extent  that  its  surface  and  vegetation 
are  nearly  identical  with  that  of  nearby  grassland.  Even  those  court- 
ship grounds  that  are  in  pastures  may  or  may  not  be  occupied  each  year 
for  a  series  of  years.  Of  10  such  grounds,  on  which  records  were  ob- 
tained from  1936  through  1938,  only  5,  or  50  percent,  were  occupied  each 
year.  Their  populations  were  fairly  stable  (see  table  3,  p.  14).  Of 
the  others,  2  were  occupied  in  1936  and  1937 ;  2  were  unused  except  in 
1936 ;  and  1  was  occupied  in  1936,  in  part  of  1937,  and  throughout  the 
entire  season  in  1938.     There  was  little  variation  in  the  prairie  chicken 


14      NORTH   AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

population  of  the  pastures  in  which  these  courtship  grounds  were  situ- 
ated, but  in  every  instance  the  vegetation  on  or  near  the  study  areas 
varied  in  density  through  grazing  or  burning.  Cover  changes  on  and 
near  courtship  areas  influenced  their  attractiveness  to  the  birds,  possibly 
to  the  point  of  determining  whether  they  would  be  occupied  and  by 
how  many  individuals. 


Table  3.- 


-Occurrences  in  3  years  of  male  prairie  cMckens  on  5  courtship  grounds 
in  Colo7~ado  County 


Observations 

Birds  observed 

Name  of  pasture 

Extremes 

Averages 

1936 

1937 

1938 

1936 

1937 

1938 

1936 

1937 

1938 

Thomas 

2 
2 
2 
2 
2 

11 
8 
14 
13 
20 

6 
6 
6 
11 
12 

7-  9 
9-11 

5-  6 

6-  8 

7-  7 

6-  9 
3-10 
3-  9 
5-11 
0-  8 

4-11 
5-  8 
3-  8 
5-13 
6-14 

8.0 
10.0 
5.5 
7.0 
7.0 

7.0 
6.0 
8.0 
9.0 
6.0 

8.0 

Do          

7.0 

Do    

7.0 

10.0 

Everett            

10.0 

Total  or  average 

10 

66 

42 

7.5 

7.2 

8.4 

NESTING 

WMle  the  males  are  still  engaged  in  their  courtship  performances, 
the  females  quietly  select  and  improve  the  nest  sites  and  attend  to 
laying,  incubating,  and  hatching  the  eggs  and  rearing  the  young. 
Nests  (pi.  4)  are  made  on  the  ground.  Of  19  examined  in  1937 
and  1938,  17  were  in  long-grass  pastures,  1  in  a  hay  meadow,  and 
1  in  a  fallow  field.  All  were  in  dead  grass  of  the  previous  year's 
growth.  Fifteen  (about  76  percent)  were  on  or  near  well-drained 
mounds  or  ridges,  and  4  were  in  poorly  drained  situations.  In  a 
choice  of  nest  sites,  cover  appeared  of  more  importance  than  topog- 
raphy and  the  structure  of  the  soil.  Twelve  (63  percent)  of  the 
study  nests  were  situated  within  10  yards  of  well-marked  trails, 
possibly  because  prairie  chickens  dislike  walking  through  heavy 
matted  vegetation  when  approaching  or  leaving  their  nests.  Cattle 
make  many  trails,  thereby  improving  nesting  areas. 

Study  nests  were  found  always  within  a  radius  of  half  a  mile 
to  a  mile  from  occupied  booming  grounds.  Sometimes  the  sites  were 
rather  distant  from  acceptable  feeding  territory,  although  flights  of 
up  to  a  mile  seemed  to  inconvenience  the  birds  very  little. 

Nests  were  merely  shallow  depressions,  about  7  inches  in  diameter, 
lined  with  bits  of  dead  grass,  twigs,  and  a  few  feathers,  presumably 
from  the  females.  All  were  more  or  less  roofed  over  because  of  the 
lapping  or  bending  over  of  surrounding  vegetation.  Entrances  faced 
in  various  directions  with  no  preference  shown.  There  was  consid- 
erable variation  in  degree  of  concealment  (pi.  5),  at  least  according 
to  human  standards;  5  nests  being  excellently,  10  well,  and  4  poorly, 
concealed.    Kapid  new  plant  growth  in  April  and  May  aided  ma- 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


Plate  4 


OJ 


«   5 


P  O 


3   5 
-2  ^ 


>    CL, 


>< 


North  American  Fauna  57,  Fish  and  Wildlife  Servii 


PLATE   5 


'.■^-    ' 


^      QJ      O 


>i  <»"  r^- 


^O 


ATTWATER'S   PRAIRIE    CHICKEN  15 

terially  in  hiding  nests ;  consequently,  some  nests  that  were  relatively 
exposed  when  found  were  well  hidden  later.  Wild  indigo  {Baptisia 
sp.),  vetch  {Vicia  ludoviciana) ,  phlox  (  Phlox  drummondii)^  peren- 
nial ragweed  {Amhrosia  psilostachya) ,  dogfennel  {EupatoHum  sp.), 
and  panic  grass  {Panicuin  sp.)  were  green  plants  that  aided  con- 
cealment materially  by  mid-May.  In  Colorado  County,  favorite 
nesting  materials  were  dry  bluestem  grass  {AndropogoTi  scoparius), 
and  paspalum   {Paspalum  dilatatum). 

The  earliest  date  for  a  nest  containing  eggs  was  reported  by  Wad- 
dell  near  Egypt,  Wharton  County,  February  25,  1925;  the  latest 
record  is  that  of  a  nest  in  Colorado  County  in  which  the  clutch 
was  completed  May  29,  1938.  In  both  1937  and  1938,  however,  the 
peak  of  the  laying  season  in  Colorado  County  was  late  March  and 
early  April.  Hens  always  laid  in  the  morning,  usually  from  7:30 
to  9,  flying  to  the  vicinity  of  their  nests  when  ready.  After  cautiously 
looking  about  or  feeding  a  bit  longer,  hens  walked  to  the  nests  and 
remained  there  for  from  about  20  minutes  to  an  hour.  The  laying 
completed,  they  regularly  walked  about  20  feet  from  the  nest,  scanned 
the  landscape,  and  flew  away.  Since  incomplete  clutches  were  un- 
guarded except  during  about  an  hour  each  day,  they  were  especially 
vulnerable  to  natural  enemies. 

Hens  under  observation  normally  laid  an  Qgg  a  day  until  the 
clutch  of  8  to  15  was  complete,  but  sometimes  they  failed  to  lay  for 
periods  of  1  to  3  days.  Clutches  usually  contained  12  eggs,  and  lay- 
ing was  generally  completed  in  about  2  weeks.  The  period  of  egg 
laying  was  sometimes  extended,  however,  when  nests  were  destroyed. 
Three  hens,  each  the  only  resident  on  a  small  unburned  plot,  re- 
nested  during  1937,  one  of  them  three  times. 

New  nests,  however,  were  placed  5  to  20  yards  from  old  ones,  and 
were  less  effectively  concealed.  Destructive  agents  had  even  greater 
opportunities  to  take  the  later  nests,  as  they  did  in  four  out  of  five 
cases.  Since  booming  ended  by  mid-May,  the  period  for  mating 
was  short.  Late  broods  were  invariably  smaller  than  early  ones, 
probably  because  late  clutches  were  small,  their  hatchability  low,  or 
their  mortality  heavy.  A  successful  season  depends  largely  on  the 
fate  of  early  nests,  so  that  a  primary  objective  of  management  should 
be  to  safeguard  these  attempts. 

Twenty-nine  eggs  of  Attwater's  prairie  chicken  measured  by  Bent 
(1932:  264)  averaged  42.3  by  31.5  millimeters  in  size,  showing  ex- 
tremes of  44.9  by  32,  42.4  by  33.5,  38.8  by  28.9,  and  39.8  by  28.6 
millimeters.  Newly  laid  eggs  were  dull  cream  or  bluish  buff  in 
color,  some  of  them  minutely  specked  with  red.  During  incubation 
the  color  of  the  eggs  became  dull  and  the  shells  shiny.  Incubation 
began  at  from  1  day  before  until  4  days  after  the  last  egg  was  laid. 


16      NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

Except  for  two  feeding  and  resting  periods  daily,  extending  from 
about  7  to  8  a.  m.  and  from  5 :30  to  6 :30  p.  m.,  hens  incubated  con- 
stantly. When  incubation  was  advanced,  morning  feeding  was  fre- 
quently dispensed  with.  Two  clutches  pipped  approximately  23  and 
24  days  after  setting  began,  in  each  instance  requiring  about  48  hours 
longer  to  hatch.  Of  71  eggs  in  7  nests,  only  3  (about  4  percent) 
were  infertile,  66  hatching  successfully.  Seemingly,  fertility  and 
hatchability  are  high  under  favorable  conditions. 

The  hatching  period  was  evidently  a  time  of  danger.  Chicks 
peeped  incessantly  and  scrambled  in  and  out  of  the  nest.  Nests 
emitted  strong  odors,  apparent  even  to  man.  Females  at  hatching 
time  appeared  nervous  and  shifted  their  positions  frequently.  Unless 
disturbed,  however,  they  did  not  leave  until  the  last  egg  had  hatched, 
after  which  they  deserted  the  nests.  In  1937  a  nest  in  which  all 
young  were  hatched  by  11 :  50  a.  m.  on  May  15  was  vacated  by  3  p.  m. 
that  day,  and  a  brood  that  was  hatching  at  8 :  30  a.  m,  on  June  2  was 
gone  24  hours  later.  One  hen  left  before  2  pipped  eggs  were  hatched 
and  before  the  natal  down  on  some  of  the  young  was  dry,  probably 
because  fire  ants  {SoUnopsis)  had  entered  the  nest. 

GROWTH  AND  DEVELOPMENT  OF  YOUNG 

When  leading  chicks  from  the  nest,  old  birds  traveled  through 
the  lightest  cover  or  followed  trails,  probably  because  heavy  matted 
vegetation  impeded  progress  and  increased  the  chance  of  chicks  get- 
ting lost.  Cow  trails  were  favorite  travel  ways.  Chicks  ranged  in 
front,  behind,  and  on  both  sides  of  the  hen  over  an  area  1  to  5  yards 
in  radius.  Interruptions  for  sporadic  feeding  and  for  frequent 
brooding,  which  was  probably  more  necessary  for  assembling  than 
for  warming  the  young,  made  progress  slow.  Hens  with  chicks  less 
than  10  days  old  (pi.  6)  seemed  mainly  concerned  with  watchfulness 
and  brooding.  Occasionally  they  caught  available  insects  or  nipped 
off  a  few  green  leaves  or  buds,  but  they  did  little  continuous  feeding. 
When  danger  threatened,  they  gave  a  warning  call,  best  described 
as  a  low  kwerr^  kwerr,  kiuerr,  and  slowly  skulked  through  the  grass 
with  head  lowered  and  wings  dangling  loosely,  almost  touching  the 
sod.  Young  birds  "froze"  with  their  bodies  closely  pressed  to  the 
ground.  Decoy  efforts  of  adult  females  were  never  so  energetic  as 
those  of  bobwhites  under  similar  circumstances.  When  hens  were 
flushed,  the  chicks  in  hiding  (pi.  6)  became  impatient  after  3  to  5 
minutes,  and  peeped  and  ran  about  in  spite  of  the  fact  that  the  object 
of  suspicion  remained.  After  the  immature  birds  of  2  to  3  weeks 
of  age  could  fly  fairly  well,  females  accompanying  them  did  not 
decoy,  but  always  flushed  freely,  the  young  doing  likewise. 

Chicks  that  were  less  than  a  week  old  were  brooded  quite  often, 
probably  in  all  for  about  50  percent  of  the  daylight  period.    Ten  birds 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


Plate  6 


Ahopc,  Chicks  about  10  days  old;  Colorado  County,  1  ex.,  n|)i)i().\iiiiai«-ly  (1  miles 
north  of  Eagle  Lake,  May  3,  1938.  Below,  Chicks  hiding;  Colorado  County, 
Tex.,  approximately  i^Yz  miles  north  of  Eagle  Lake,  May  3,  1938.  (Photos 
from  Texas  Game,  Fish,  and  Oyster  Commission;  E.  P.  Haddon.) 


ATTWATER'S   PRAIRIE    CHICKEN  17 

about  2  days  old  were  brooded  42  minutes  out  of  the  li^  hours  during 
which  they  were  watched  on  May  4,  1937.  Their  position  during 
brooding  was  interesting.  Hens  squatted  low  with  legs  at  an  angle 
of  about  30  degrees  with  the  ground.  Wings  were  drooped  and 
feathers  of  the  underparts  were  ruffled.  Some  chicks  scrambled  up 
and  under  the  wings.  When  the  brooding  hens  were  frightened  and 
suddenly  stood  erect,  usually  only  two  or  three  chicks  were  visible; 
the  others,  however,  tumbled  from  beneath  her  wings  a  few  moments 
later.  As  the  chicks  grew  older,  the  time  spent  brooding  diminished ; 
those  2  weeks  old  apparently  were  brooded  little  except  early  in  the 
morning,  during  inclement  weather,  and  at  night. 

Newly  hatched  chicks  are  about  the  gize  of  day-old  bantams,  and 
their  coloration  is  nearly  identical  with  that  of  young  bronze  turkeys. 
The  basic,  buffy  yellow  is  streaked  with  gray  on  head  and  upper- 
parts.  Growth  and  development  are  rapid.  Wing  feathers  appear 
almost  at  once;  week-old  chicks  have  primaries  approximately  five- 
eighths  of  an  inch  long.  Chicks  fly  when  2  weeks  old.  Except  for 
differences  in  the  length  of  the  tail  and  legs,  they  are  about  the  size 
of  English  sparrowg.  When  3  weeks  of  age,  youngsters  are  almost 
as  large  as  starlings  and  can  make  sustained  flights  of  40  yards  or 
more.  At  4  or  5  weeks,  young  birds  approximate  the  size  of  mature 
bobwhites,  and  often  fly  a  hundred  yards  before  alighting.  When 
6  or  7  weeks  old,  the  young  are  about  half  grown  and  at  8  or  9  weeks 
they  are  three-fourths  the  size  of  adultg.  Youngsters  10  to  12  weeks 
old  can  scarcely  be  differentiated  from  the  old  birds  in  the  field. 
Weight  evidently  does  not  increase  as  rapidly  as  size,  however,  for 
two  birds  approximately  3  months  old  were  more  than  a  pound  lighter 
than  mature  individuals. 

As  young  prairie  chickens  grow  in  size,  all  cannot,  of  course,  main- 
tain a  brooding  position  under  the  sheltering  body  of  the  mother. 
Usually  by  the  time  they  are  about  3  weeks  old  some  are  forced  out- 
side; there  they  sleep  with  bodies  pressed  closely  to  that  of  the  hen. 
When  4  to  5  weeks  of  age,  two  or  three  chicks  sometimes  crowd  under 
their  mother,  but  the  remainder  roost  from  a  few  inches  to  about  2  feet 
away.  At  6  to  7  weeks,  young  birds  adopt  the  roosting  formation  of 
adults.  Flocks  of  Attwater's  prairie  chickens  sleep  about  a  foot  or  so 
apart,  the  individuals  facing  in  different  directions.  Boosting  spots 
vary  in  size  from  1  to  3  square  yards  or  more,  depending  on  the  number 
of  birds  in  the  group.  The  number  of  scats  left  at  a  roosting  site 
is  not  an  absolutely  accurate  index  to  the  number  of  birds  in  a  flock, 
because  slight  shifting  of  individuals  during  the  night  brings  about  the 
deposition  of  more  than  one  pile  by  a  bird. 

Chicks  about  2  weeks  old  take  vigorous  dust  baths,  a  habit  that  is 
indulged  in  regularly  throughout  life  when  dry,  powdery  material  is 


18       NORTH   AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

available.  Prairie  chickens  generally  dust  during  the  midday  rest 
period  that  extends  from  about  10  a.  m.  to  4  p.  m.  Old  pocket  gopher 
mounds  and  cattle  wallows  are  favorite  places.  Some  birds  use  the 
same  dust  bath  more  than  once. 


BROOD  SIZE 

The  size  of  the  brood  generally  decreases  with  the  age  of  the  young. 
Of  48  broods  on  which  accurate  counts  were  kept  (table  4,  below)  6 
from  1  to  3  days  old  contained  64  young,  averaging  10.6  birds  each. 
Three  broods  estimated  to  be  5  to  10  days  old  contained  only  14  chicks 
averaging  4.6  each.  Four  broods  15  to  27  days  old  had  22  young,  or 
an  average  of  5.5.  Fifteen  families  over  4  and  under  6  weeks  of  age 
aggregated  80  young  and  averaged  5.3.  Twenty  groups  over  6  weeks 
totaled  80  young  and  averaged  4  each.  The  average  size  (5.3  young) 
of  15  families,  estimated  to  be  over  4  but  under  6  weeks  of  age,  was 
exactly  half  the  average  size  (10.6)  of  6  new  broods.  The  average 
size  (5.3)  of  15  families  over  4  but  under  6  weeks  old  was  but  slightly 
larger  than  the  average  size  (4.0)  of  20  families  older  than  6  weeks. 
Therefore,  it  appears  that  juvenile  mortality  is  heaviest  during  the 
first  4  weeks  and  comparatively  light  thereafter. 


Table  4. — Size  of  iroods  and  number  of  chicks  counted  during  May, 

July 

June,  and 

County 

Date 

Family 

groups 

observed 

Chicks 

per 
group 

Chicks  per 
average 
group 

May    4 
May  15 
May  18 
May  23 
May  28 
May  29 
May  31 

1 

1 
1 
3 
3 

1 
2 

10 
12 

12 

2,4,2 

7,  9, 11 

8 

4,8 

10.00 

Do                  

12.00 

Do                                     

12.00 

Do                     -      

2.66 

Do                  

9.00 

Do                                       ---      

8.00 

Do                               -      

6.00 

12 

89 

7.41 

June    2 
June     3 
June     8 
June  10 
June  24 

4 
1 
2 
2 

3 

6, 9, 4, 2 

10 

3,3 

4,8 

5,4,3 

6.33 

Do                                           

10.00 

Do                             

3.00 

Do                      

6.00 

Jefferson 

4.00 

Total  or  average  for  June 

12 

61 

5.08 

July     1 
July     8 
July   14 
July    17 
July    19 
July   26 

3 
2 
1 
4 
6 
2 

5,5,6 

3,3 

7 

10, 8, 1,  3 

10, 2,  2, 4,  5,  2 

10,5 

5.33 

Colorado 

3.00 
7.00 

6.00 

Do                  

4.16 

Colorado 

8.00 

Total  or  average  for  July 

18 

92 

5.11 

Aug.  12 
Sept.    2 
Sept.    3 
Sept.    4 

1 
3 
1 
1 

3 

5,3,3 

3 

4 

3.00 

3.66 

Do                     

3.00 

Do 

4.00 

Total  or  average  for  August,  September 

5 

18 

3.60 

48 

263 

5.48 

ATTWATER'S   PRAIRIE    CHICKEN  19 

JUVENILE  MORTALITY 

Although  much  remains  to  be  learned  about  juvenile  mortality, 
its  causes  were  fairly  well  established  in  some  instances.  Chicks  are 
sometimes  trapped  and  drowned  in  rice  fields  at  the  time  of  flooding 
(usually  about  May  10).  In  1925,  near  Egypt,  Wharton  County, 
Waddell  and  others  picked  up  hatfuls  of  chicks  and  carried  them 
beyond  the  levees.  In  1937  a  farmer  near  Eagle  Lake  similarly  res- 
cued a  brood.  The  number  of  chicks  annually  saved  from  this 
hazard,  however,  is  probably  insignificant  in  contrast  to  those  lost. 
Prairie  fires  kill  young  and,  as  stated  on  page  42,  burning  is  still 
common  in  certain  areas  at  nesting  and  brooding  time.  Unfavorable 
weather,  especially  rains  (pp.  32  to  35)  and  natural  enemies  (p.  39), 
account  for  the  death  of  some  young  birds,  but  no  small  percentage 
of  these  may  be  chicks  that  are  lost. 

Chicks  stray  from  the  brood  more  often  than  one  might  suspect. 
During  April,  May,  and  June,  1937,  no  fewer  than  13  strays  were 
seen,  all  under  4  weeks  old.  Usually  they  occurred  as  singles,  but 
sometimes  in  pairs  and  trios.  How  the  youngsters  became  lost,  of 
course,  was  usually  unknown,  but  several  reasons  were  apparent. 
The  characteristic  loose  feeding  formation  of  broods  possibly  con- 
tributed to  straying;  also,  broods  usually  scattered  widely  and  flew 
far  when  disturbed;  and,  possibly  most  significant  of  all,  adults  did 
not  appear  to  have  a  highly  developed  rallying  call  that  doubtless 
would  be  of  assistance  in  reassembling  youngsters. 

Lost  chicks  evidently  join  other  groups  occasionally,  as  hens  ac- 
companied by  young  of  varied  sizes  were  several  times  noted  in  1937. 
Once  two  chicks,  about  2  and  3  weeks  old,  respectively,  were  seen 
with  two  molting  males.  Higher  population  levels  might  increase 
the  frequency  of  adoptions. 

FAMILY  DISINTEGRATION 

Many  young  Attwater's  prairie  chickens  6  to  8  weeks  old  leave  the 
family  groups  and  take  up  life  on  their  own,  but,  as  is  true  with 
domestic  chickens,  all  young  do  not  leave  the  hen  at  the  same  time; 
disintegration  of  the  family  group  is  gradual.  Some  young  remain 
with  the  hen  well  into  the  fall.  Unattached  young,  6  weeks  of  age 
or  older,  as  distinguished  from  lost  chicks  less  than  a  month  old, 
became  noticeable  late  in  June  and  they  were  frequently  seen  after 
July.  Family  disintegration  after  6  weeks  or  thereabouts  is  normal. 
Young  prairie  chickens  at  that  age  seem  as  capable  of  foraging  and 
resisting  adverse  weather  as  are  the  adults. 


20      NORTH  AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

ANNUAL  INCREASE 

The  actual  survival  of  young  prairie  chickens  (table  5,  below)  prob- 
ably is  always  well  below  the  potential  yield  (12  or  so  young  from 
each  hen)  even  when  favorable  weather  conditions  obtain  during 
the  critical  breeding  season. 


Table  5 

. — Young  and  adult  Mrds  observed 

in  census  after  June  30, 1937 

Date 

Area 

Adults 

Young 

County 

Males 

Females 

Sex  un- 
known 

Total 

Families 

Strays 

Total 

Brazoria 

Victoria 

July    1 
July  14 
July  17 
July  19 
July  26 
July   27 
Aug.  12 
Sept.    1 

Acres 
585 
921 

1,080 
530 

1,450 
851 

1,282 

2,000 

Number 
2 
1 
1 
3 
0 
2 
1 
1 

Number 
4 
1 
4 
8 
2 
0 
1 
5 

Number 
2 
6 

23 
S3 
4 
2 
2 
8 

Number 
8 
8 
28 
64 
6 
4 
4 
14 

Number 

5,5,6 

7 

10,  8, 1, 3 

10, 2, 2, 4, 5, 1 

11,5 

3 

3 

5,3,3 

Number 

1, 1, 1, 1, 1 

1,2 

2, 1, 1, 1, 1 

1, 1, 2, 1, 1, 1 

2,3 

1 

1 

1,2,1,3 

Number 
21 
10 

Refugio 

28 

Do 

32 

Colorado. 

Brazoria 

Harris           .    . 

21 

4 
4 

Colorado 

18 

Total 

8,699 

11 

25 

100 

136 

103 

35 

138 

In  a  rope  count  on  or  after  July  1,  1937,  138  young  as  compared 
with  136  adults  (about  1:1)  were  enumerated  on  an  area  of  more 
than  8,699  acres.  At  this  time  most  of  the  counted  birds  were  4 
weeks  old  or  more  and  were  beyond  the  age  when  mortality  is  thought 
to  be  most  severe.  The  increase  on  the  counted  areas,  then,  was  only 
about  100  percent  in  spite  of  the  fact  that  food,  cover,  and  weather 
conditions  were  favorable.  A  100  percent  increase  of  prairie 
chickens  in  any  one  year  is  very  good,  and  the  arguments  for  long 
open  seasons  and  large  bag  limits,  based  on  the  potential  annual 
increase  (12  chicks  for  each  hen,  or  about  600  percent  a  year),  evi- 
dently are  fallacious. 


FLOCKING 


Late  in  summer  and  early  in  fall,  the  prairie  chickens  displayed  no 
marked  tendency  to  combine  into  stable  groups.  In  August  and 
September  of  1936  and  1937  well  over  half  the  birds  observed  in 
Colorado  County  were  recorded  as  singles,  pairs,  and  trios,  although 
small  groups  of  4  to  6  were  not  uncommon.  Occasional  larger  flocks 
were  recorded,  but  these  appeared  to  be  temporary.  In  Colorado 
County,  at  about  noon  on  September  1,  1937,  a  flock  of  15  to  25  birds 
was  noticed  in  a  cotton  field.  On  the  following  3  days  at  the  same 
hour  11,  15,  and  9  birds,  respectively,  were  present  in  that  field; 
but  they  had  come  in  between  9 :  30  and  11 :  30  as  singles,  pairs,  and 
in  small  groups  not  exceeding  5  birds  each.  Between  4  p.  m.  and 
dark  they  left  the  field  as  they  had  come.  Again  in  Colorado 
County,  at  6  p.  m.  on  September  3,  1937,  another  group  of  16  birds 
found  in  a  pasture  came  together  as  follows :  At  5 :  40  p.  m.  a  group 


ATTWATER'S  prairie   CHlCKElSr  21 

of  8  flushed  approximately  1  mile  from  the  spot  where  the  large 
flock  was  later  noted,  and  as  they  flew  over  the  prairie,  a  pair,  a 
single,  a  trio,  and  another  pair  joined  the  original  group.  AH  set- 
tled and  fed  together  for  a  time,  but  the  be\^  disintegTated  by  dusk. 
Like  instances  suggest  that  early  fall  flocks  of  a  dozen  or  so  birds 
are  unstable  groups  brought  together  largely  by  chance. 

In  fall,  after  the  weather  turned  cool,  groups  of  prairie  chickens 
became  the  rule  rather  than  the  exception.  Early  November  bevies 
generally  contained  4  to  12  birds  each,  but  large  flocks  became  in- 
creasingly common  from  about  December  1  to  the  onset  of  the  breed- 
ing season.  Late  in  winter  (January)  Guy  Ferguson,  State  game 
warden,  Sinton,  Tex.,  observed  flocks  in  Kefugio  and  Aransas  Coun- 
ties that  contained  more  than  a  hundred  birds.  Wardens  Waddell 
in  Colorado,  Austin,  and  Wharton  Counties,  and  McClosky  in  Vic- 
toria County,  reported  winter  aggregations  of  about  the  same  size. 
In  1936,  J.  O.  Linney,  foreman,  Salt  Creek  (Hallahan)  ranch,  Re- 
fugio and  Aransas  Counties,  noticed  late  winter  concentrations  esti- 
mated to  contain  250  to  300  individuals.  The  writer  has  not  observed 
such  large  winter  flocks,  possibly  because  he  has  not  made  observa- 
tions in  areas  where  the  birds  were  sufficiently  numerous.  January 
assemblages  of  25  to  35  birds  were  not  uncommon,  however,  in  Colo- 
rado County.  Despite  the  fact  that  large  flocks  became  more  fre- 
quent from  November  until  the  breeding  season,  small  groups  of  8 
or  fewer  birds  or  singles  were  always  to  be  found.  All  packs  ob- 
served in  Colorado  County  late  in  November,  December  and  January 
contained  birds  of  only  one  sex.  Late  in  January,  residents  of  the 
coastal  country  eagerly  listen  for  the  first  booming  calls,  which, 
besides  promoting  rapid  disintegration  of  winter  flocks,  signal  the 
departure  of  winter  and  the  coming  of  spring. 

seasonal  movements 
Spring 

Comprehensive  data  on  prairie  chicken  movements  are  lacking,  but 
the  records  obtained  in  1937  are  of  interest.  Two  broods  that  were 
observed  two  or  more  times  daily  from  the  time  the}?^  were  hatched 
until  they  were  7  and  12  days  old,  respectively,  were,  at  last  observa- 
tion, less  than  half  a  mile  from  the  nest  sites.  Another  brood,  esti- 
mated to  be  8  days  old  when  first  discovered  on  June  2,  was  within  150 
yards  of  the  same  spot  at  various  hours  during  the  next  6  days.  A 
fourth  brood,  about  3  days  old  on  April  29,  remained  within  400  yards 
of  a  certain  windmill  from  April  29  through  May  31.  A  640-acre 
pasture  that  contained  four  broods,  all  under  2  weeks  of  age  when 
rope  counted  on  June  2,  likewise  harbored  four  broods  10  days  later. 


22       NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVlCiJ 

If  this  is  indicative,  the  prairie  chickens  under  observation  spent 
their  first  several  weeks  of  life  in  close  proximity  to  the  places  where 
hatched.  The  daily  cruising  radius  of  a  brood  apparently  was  small, 
seemingly  less  than  300  yards  in  the  case  of  birds  under  4  weeks  old 
in  a  favorable  environment.  Some  30  broods  observed  between  May 
1  and  June  1  were  found  in  light  cover  on  or  near  hardpan  flats  and 
recent  burns,  indicating  a  distinct  preference  for  those  types  of  habitat. 

SUMMEE 

An  extensive  movement  involving  both  young  and  adult  prairie 
chickens  in  Colorado  County  began  about  June  1,  1937,  when  many 
of  the  young  were  3  to  5  weeks  old,  and  lasted  until  about  June 
30.  The  sudden  scarcity  of  the  birds  in  places  where  they  had  been 
common  only  a  few  days  before  was  striking.  A  1,000-acre  pasture 
that  contained  37  individuals  (16  old  and  21  young)  on  June  2,  held 
only  16  in  all  on  June  10.  As  the  prairie  chickens  decreased  in  some 
pastures,  they  increased  in  others.  A  460-acre  pasture  that  was  un- 
occupied on  May  1  contained  14  birds  on  June  8  and  23  on  July  26. 

This  movement  from  the  spring  range  was  by  stages.  One  brood 
that  was  watched  closely  made  trips  of  approximately  1  mile,  three- 
fourths  mile,  and  1^  miles  in  6  days  from  June  2  through  June  8. 
After  the  first  major  movement,  this  family  remained  for  3  days  in  an 
area  less  than  500  yards  in  diameter ;  their  droppings  in  piles  formed  a 
triangle  with  sides  of  5,  15,  and  17  yards,  respectively.  The  move- 
ment of  a  combined  brood  of  3  hens  and  16  to  25  young  are  recorded 
in  figure  2,  p.  23. 

Leopold  (1933:  291)  reports  thai^- 

All  observers  unanimously  and  independently  report  a  strong  tendency  for  the 
grown  young  of  most  species  of  grouse  to  seek  the  vicinity  of  drinking  water 
in  late  summer  and  fall,  but  whether  they  do  this  out  of  choice  or  necessity 
is  not  known. 

The  early  summer  movement  of  young  and  adult  Attwater's 
prairie  chickens  also  was  to  the  vicinity  of  surface  water,  but  it 
was  to  water  near  which  there  also  was  shade.  Pastures  having  an 
abundance  of  surface  water  but  little  or  no  shade-producing  cover 
had  few  if  any  birds  after  mid-June.  Likewise,  places  in  which 
dense  stands  of  weeds,  shrubs,  or  tall  grass  were  abundant,  but  sur- 
face water  scarce,  were  sparsely  populated.  More  than  95  percent  of 
the  more  than  600  Attwater's  prairie  chickens  observed  from  June 
24  through  September  4,  1937,  were  in  heavy  cover  within  a  mile, 
generally  within  less  than  half  a  mile  of  surface  water. 

The  beginning  of  the  summer  movement  is  synchronous  with  the 
drjdng  up  of  the  wild  indigo  {Baptisia,  pi.  7),  a  plant  that  fur- 
nishes the  principal  shade  on  burns  and  heavily  grazed  areas  from 
April  through  May.  Prairie  chickens  require  abundant  shade  in  sum- 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


PLATE  7 


B50688:   B49718A 


Above,  Wild  indigo  {Baptisia)  in  a  closely  grazed  pasture;  Austin  County,  Tex., 
approximately  8  miles  southeast  of  Sealy,  April  10,  1938.  Below,  Shocked 
grain  and  wa.ste  in  rice  fields  sometimes  attract  prairie  chickens;  Colorado 
County,  Tex.,  3  miles  northeast  of  Eagle  Lake,  September  5,  1936.  (Photos 
by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN 


23 


mer,  for  birds  that  were  herded  from  such  cover  at  midday  panted 
vigorously,  drooped  their  wings,  and  showed  other  signs  of  discomfort. 
They  evidently  rarely  drink  from  surface  water.  In  1937,  birds 
near  water  were  closely  observed,  but  only  one  was  seen  to  drink 
during  the  entire  summer.  That  was  in  Colorado  County  on  June 
1,  1937,  when  a  chick  about  3  weeks  old  drank  a  few  times  from  a 
puddle  formed  by  water  from  a  leaking  windmill.  The  soft  mud 
bordering  ponds  in  inhabited  prairie  chicken  range  in  Brazoria, 
Colorado,  and  Austin  Counties  was  examined  thoroughly  at  various 
times,  but  tracks  of  this  species  were  never  found.     Grasshoppers 


FiGUBE  2. — Movements  of  a  combined  brood,  May  1  to  July  26,  1937,  Colorado 
County.  Birds  seen  in  areas  as  follows :  1,  May  1  to  28 ;  2,  June  10  to  July 
10;  3,  July  15  to  26. 

and  other  favorite  foods  were  frequently  more  abundant  in  surmner 
in  heavy  cover  near  water,  but  the  food  factor  was  not  thought  to 
be  of  great  importance  at  the  time.  The  summer  movements  of 
prairie  chickens  to  heavy  cover  near  water  are  not  satisfactorily  ex- 
plainable on  the  basis  of  cover,  water,  and  food,  but  these  habitat 
conditions  must  be  provided  where  stable  populations  are  desired. 
After  they  found  a  satisfactory  summer  range,  the  prairie  chickens 
moved  little  until  fall,  unless  their  summer  territory  was  depleted 
or  that  nearby  was  more  suitable.  The  population  of  a  460-acre 
pasture  in  Colorado  County  remained  at  nearly  the  same  level  (25 


24       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND    WILDLIFE    SERVICE 

to  36  birds)  from  July  26  through  September  3,  1937.  The  birds 
that  rested  in  this  area  at  noon  each  day,  however,  foraged  and 
roosted  largely  in  adjoining  pastures,  but  their  range  was  never  more 
than  114  miles  and  usually  under  half  a  mile. 

Rains  in  1937  sufficiently  heavy  to  collect  in  low  spots  caused  tem- 
porary spreading  of  prairie  chickens  from  previously  occupied  areas. 
As  the  temporary  water  disappeared,  however,  the  birds  again  con- 
centrated. 

Fall  and  Winter 

Populations  that  had  been  rather  stable  in  certain  pastures  in  Colo- 
rado County  during  the  summer  months  of  1937  began  shifting  early 
in  fall.  About  25  birds  that  were  summer  residents  of  the  M.  Shin- 
dler  cotton  field  from  July  through  August  were  absent  after  Sep- 
tember 4.  Two  thousand  acres  of  regularly  censused  pasture  where 
prairie  chickens  were  common  in  summer  contained  only  9  birds  when 
rope  counted  on  October  22.  While  the  birds  decreased  generally 
in  the  large  pastures,  they  increased  around  small  farms  near  Sealy, 
Austin  County ;  Lissie,  Wharton  County ;  and  Bernardo  and  Chester- 
ville,  Colorado  County — territory  5  to  10  miles  removed  from  the 
pastures  in  which  birds  had  been  most  common  during  the  preceding 
spring  and  summer. 

Distances  traveled  daily  were  evidently  great  in  some  instance^.  A 
bird  killed  by  a  farmer  at  8  a.  m.  on  September  1,  1936,  was  L  .lown 
to  have  traveled  at  least  3  miles  since  dawn,  because  its  cror  was 
filled  with  rice  and  the  nearest  rice  field  was  that  distant.  Two  in- 
dividuals, observed  for  2  hours  on  the  afternoon  of  October  22,  1937, 
traveled  approximately  ly^  miles  southeast  of  the  point  where  first 
seen.  When  finally  flushed,  they  flew  an  additional  2  miles  or  so  in 
the  same  direction.  A  flock  of  four  birds  observed  from  4  p.  m.  to 
6:15  p.  m.  on  January  4,  1938,  traveled  more  than  1%  miles.  The 
movement  was  in  a  circular  direction,  however,  for  at  nightfall,  the 
birds  were  less  than  half  a  mile  from  the  point  where  they  were  first 
observed.  Cool  weather,  fall  rains,  and  a  seasonal  abundance  of 
food  and  cover,  especially  in  the  vicinity  of  farming  co  nmunities, 
probably  were  important  in  promoting  the  general  fall  scattering 
and  the  long  daily  trips  the  prairie  chickens  made  in  territory  that 
was  sparsely  populated  at  other  seasons.  The  birds  reconcentrated 
in  large  pastures,  however,  as  fall  passed  into  winter. 

The  population  of  the  Everett  pasture  (640  acres),  Colorado 
County,  increased  from  November  3,  1937,  through  January  28,  1938 ; 
five  censuses  during  that  period  showing  46,  58,  56  to  58,  73,  and  84 
birds,  respectively.  Excellent  food  and  cover  conditions  prevailed, 
for  the  area  was  lightly  grazed.  This  increase  in  the  number  of 
birds  apparently  resulted  from  influxes  from  adjoining  areas.    After 


ATTWATER'S   PRAIRIE    CHICKEN  25 

November  15,  few  fluctuations  in  numbers  between  different  pastures 
were  reported  by  fence  riders  and  others.  Pastures  that  contained 
the  greatest  numbers  in  November  and  December  1937  also  harbored 
the  largest  breeding  populations  the  following  spring. 

The  data  at  hand  show  that  late  in  fall,  probably  by  about  Novem- 
ber 15,  the  prairie  chickens  move  to  pastures  where  food  and  cover 
conditions  are  adequate.  Having  found  such  an  area,  they  remain 
until  spring.  Probably  the  best  way  to  attract  a  good  breeding 
population,  therefore,  is  to  provide  suitable  food  and  cover  conditions 
during  the  preceding  winter. 

FOOD 

Data  on  the  food  of  Attwater's  prairie  chicken  were  derived  mainly 
from  analyses  of  21  stomachs  (crops,  or  gizzards,  or  both)  and  more 
than  200  droppings  (scats).  Additional  information  was  obtained 
by  watching  feeding  birds  at  close  range  through  field  glasses.  Of 
the  21  stomachs,  18  were  of  adult  prairie  chickens,  2  of  chicks  ap- 
proximately 10  days  old,  and  1  of  a  juvenile  about  7  weeks  old. 
Specimens  were  obtained  as  follows:  6  in  winter  (January  and 
February),  5  in  spring  (April  and  May),  5  in  summer  (June  through 
August),  and  5  in  fall  (September  through  November).  J.  H.  Gaut 
collected  3  stomachs  near  East  Bernard,  Wliarton  County,  in  May 
1905.  Over  the  period  beginning  September  1936  and  ending  Au- 
gust 1938,  2  stomachs  were  obtained  in  Austin  County,  4  in  Refugio 
CounVy,  and  12  in  Colorado  County.  As  the  crops  and  gizzards 
of  alH  birds  found  killed  by  automobiles,  predators,  poachers,  and 
from  other  causes  were  saved,  it  was  necessary  to  collect  only  11 
specimens  to  balance  the  series  according  to  seasons. 

Except  during  the  breeding  season,  adult  prairie  chickens  regu- 
larly feed  twice  daily,  early  in  the  morning  (dawn  to  about  8  a.  m.), 
and  late  in  the  afternoon  (4  p.  m.  to  dark).  Occasional  bits  of  food 
are  picked  up  throughout  the  day,  but  the  gullets  of  specimens  col- 
lected about  noon  are  usually  empty  or  nearly  so.  The  food  capacity 
of  prairie  chickens  is  large.  Gullets  frequently  contain  about  20 
cubic  centimeters,  and  the  gizzard  about  30  cubic  centimeters,  of 
material.  Since  the  birds  ordinarily  feed  slowly  and  deliberately, 
apparently  selecting  their  food  with  great  care,  it  is  not  surprising 
that  their  diet  in  favorable  areas  is  varied.  Stomachs  have  been 
examined  that  contained  29  kinds  of  food  and  more  than  1,300  items ; 
stomachs  rarely  contain  less  than  13  kinds  of  food  of  500  items. 
Mature  birds  evidently  feed  mostly  on  vegetation  at  all  seasons, 
for  the  stomachs  of  18  adults  (table  6,  p.  26)  contained  88.28  percent 
of  plant  material  and  11.72  percent  of  insects.  Animal  matter  prob- 
ably ranks  higher  than  plants  in  the  diet  of  young  birds,  however, 


26      NORTH  AMERICAN  FAUNA    57,   PISH  AND  WILDLIFE    SERVICE 

for  the  stomachs  of  2  chicks  and  a  juvenile  (table  7,  below)  contained 
88.5  percent  of  insects.  The  ratio  of  plant  to  animal  food  varies 
according  to  season  (table  8,  below),  insects,  for  instance,  apparently 
being  eaten  in  greatest  quantity  in  summer. 

Table  6. — Composition  of  the  stomach  ^  contents  of  18  adult  prairie  chickens 


Item 

Stomachs 

in  which 

found 

Quantity 
present 

Item 

Stomachs 

in  which 

found 

Quantity 
present 

Number 

18 

12 

16 

5 

6 

Percent 

88.^8 

27.  n 

55.67 

1.30 

4.20 

Animal  matter 

Number 
18 

17 
8 
1 
1 

11 

Percent 

11  7i 

Leaves  and  stems 

Seeds  and  pods       

Insects: 

Adults 

10  83 

Buds  and  flowers 

Miscellaneous '. 

Eggs  and  larvae.. 

Round  worms 

Prairie  chicken  feathers... 
Qrit  . 

0.89 

1  Crops  or  gizzards,  or  both. 

'  M^oody  pod  septa,  root  stocks,  and  the  like. 

8  Trace. 

Table  7. — Composition  of  the  stomach  contents  of  three  younff  prairie  chickens 


Item 

Stomachs 

in  which 

found 

Quantity 
present 

Item 

Stomachs 

in  which 

found 

Quantity 
present 

Vegetable  matter 

Number 
2 
2 
1 

Percent 
11.6 
1.5 
10.0 

Animal  matter 

Number 
3 

3 
2 

Percent 
88.  S 

Seeds  or  pods ... 

Insects: 

Adults         

86.0 

Eggs  or  larvae 

2.5 

Table  8. — Percentage  of  plant  and  animal  food  according  to  season 


Item 

Spring 

Summer 

Fall 

Winter 

Whole  year 

Plants 

94.25 
5.75 

71.0 
29.0 

85.8 
14.2 

95.0 
5.0 

86.51 

13.49 

Total  .- 

100. 00 

100.0 

100.0 

100.0 

100. 00 

The  data  at  hand  indicate  that  Attwater's  prairie  chickens  are 
preponderantly  granivorous,  for  seeds  and  seed  pods  made  up  slightly 
more  than  50  percent  of  all  the  material  in  the  stomachs  of  18  adults. 
Much  succulent  vegetation  is  eaten,  however,  including  leaves,  buds, 
flowers,  and  root  stocks.  The  birds  also  consume  insect  eggs,  larvae, 
and  adults,  as  shown  in  tables  6  and  7. 

Parts  of  some  50  kinds  of  plants  and  more  than  65  species  of 
insects  were  identified  in  the  food  from  stomachs  or  scats,  or  by 
observations  in  the  field.  The  names  of  these  plants  and  insects 
together  with  the  seasons  when  they  are  known  to  be  eaten,  are 
listed  in  tables  9  and  10,  pp.  27  and  28. 


ATTWATER'S   PRAIRIE    CHICKEN 
Taklb  9. — Plant  foods  (56)  of  AtHcater's  prairie  chicken 


27 


Plant 


Marsileaceae:  Pepperwort  (Marsilea) 

Poaceae: 

Paspalum  (Paspalum  ciliatifolium  type) .  - 

Bull  grass  {Paspalum  boscianum  ?) 

Paspalum  (Paspalum  plicatulum).. 

Panic  grass  (Panicum  scribnerianum) 

Panic  grass  {Panicum  spp.) -. 

Crabgrass  {Digitaria) 

Sandbur  {Cenchrus) 

Hegari  {Sorghum  vulgare) 

Rice  {Oryza  saliva) 

Corn  {Zea  mays).-. 

Cyperaceae: 

Beakrush  (Rynchospora) 

Sedge  {Carei)- 

Commelinaceae:  Dayflower  {Commelina  cris- 

pa). 
Alliaceae:  Wild  onion  {Nothoscordum  bivalve)... 

Liliaceae:  (Undetermined) 

Lcucojaceae:  Stargrass  {Hypoxis) 

Convallariaceae:  Solomons  seal  {Polygonatum 

commulalum) . 
Ixiaceae:    Blue-eyed-grass    {Sisyrinchium  va- 

rians). 
Polygonaceae:  Dock  (Rumex  near  crispus  type), 
Ranuneulaceae:  Buttercup  {Ranunculus  near 
hispidus) . 

Rosaceae:  Dewberry  {Rubv^) 

Malaceae:  Chokeberry  {Pyrus) 

Mimosaceae: 

Sensitive  briar  {Neptunia  Lutea) 

Mimosa  {Mimosa) -. 

Acacia  {Acacia)... 

Cassiaceae:  Partridge-pea  {Chamaecri»ta  fas- 

ciculaia) . 
Fabaceae: 

Wild  pea  (undet.) .-. 

Wild  pea  {Lathy ruspusillus).. 

Peanuts  {Arachis  hypogaea) 

Oxalidaceae:  Woodsorrel  {Oxalis) 

Euphorbiaceae: 

Doveweed(Cro<on  capitatui) 

Doveweed  (C  glandulosus) -. 

Doveweed  (C.  monanthogynut) 

Spurge  {Euphorbia) 

Spurge  ( Crotonopsis  linearis) 

Spurge  (Chamaesyce) 

Vitaceae:  Grape  (Vilis) 

Malvaceae:  Mallow  {Malva) 

Epilobiaceae:  Gaura  {Qaura) 

Ammiaceae  {Cynosciadium) 

Convolvulaceae: 

Bindweed  {Convolvulus) 

Evolvulus 

Polemoniaceae:  Phlox  {Phlox  drummondi) 

Boraginaceae:  Gromwell  {Lithospermum) 

Verbenaceae: 

Fog  fruit  (Phyla  nodiflora) 

Verbena  (Verbena) 

Acanthaceae:  Ruellia    (Ruellia    ciliosa    var. 

humilis). 
Rubiaeeae: 

Buttonweed  (Diodia  teres) 

Buttonweed  (Diodia  virginiana) 

Bedstraw  (Galium) 

Ambrosiaeeae: 

Marsh-elder  (Iva  ciliata) 

Perennial  ragweed  (Ambrosia  psilostachya) . 
Carduaceae: 

Thistle  (Carduus) 

Tickweed  ( Coreopsis) 

Cichoriaceae :  {Serinea  oppositifolia) 


Parts  eaten 


Leaves. 


Leaves,  seeds. 

Seeds. 

do.. 

do.. 

do 

do 


.do. 
.do- 
-do. 
.do- 


do 

Seeds,  leaves.. 
Leaves,  seeds. 


Leaves,  flowers. 

Seeds 

Leaves,  seeds... 
Seeds.- 


Seeds,  pods. 


Seeds 

Leaves,  seeds,  pods. 


Seeds,  fruits 

Flowers,  fruits. 


Leaves,  flowers,  seeds. 

Leaves,  seeds.. 

Seeds 

Seeds,  flowers 


Flowers 

Leaves 

Fruits 

Leaves,  seeds. 


Seeds 

do. 

Seeds,  leaves. 

Seeds 

do 

do 

Seeds,  fruits.. 
Seeds,  pods.. 

Pods.. 

Leaves 


Seeds 

Seeds,  pods. 

Seeds,  pods,  flowers. 
Seeds 


Leaves,  flowers,  fruit 

Leaves 

Leaves,    stems,    seeds, 
buds,  pods,  flowers. 


Seeds 

do... 

Leaves,  seeds. 


do. 

Seeds.. 


do 

Flowers 

Seeds,  pods. 


Seasons  when 
eaten  i 


Wi.... 

Sp,  su,  au,  wi 

Au.... 

Sp,  su,  au 

Sp. 

Sp 

Au... 

Wi 

Su,  au. 

Au,  wi 

Sp-.. 

Su,  au,  wi 

Au 

Au 

Wi.. 

Su,  wi-. 

Sp..-. 

Su--. 

Sp,  su 

Wi 

Wi.sp- 

Sp... 

Sp.- 

Au,  wi,sp 

Su,  au,  wi 

Wi 

Su,  au-. 

Sp 

Wi 

Au 

Wi,  sp,  su 

Au,  wi 

Au,  wi 

Au 

Au,  wi,  sp 

Au 

Au 

Su 

Sp-. 

Sp 

Wi 

Sp 

Sp.. 

Sp,  su 

Su.... 

Sp,  wi,  au 

Wi-.- 

Au,  wi 

Su,  au,  wi 

Su 

Sp,  su,  au 

Wi 

Au,  wi 

Sp 

Sp 

Sp,  su... 


Source  of 
data' 


St. 

St,  sc. 

St. 

St. 

St. 

St. 

St. 

St. 

Si. 

Si,  St. 

St. 

St. 
St. 
St. 

St. 
St. 
St,  si. 

St. 

St. 

St. 
St. 

St. 
St,  si. 

St,  si. 
St,  sc. 
St. 
St,  si. 


St. 
St. 
Si. 
St,  sc,  si. 

St,  sc,  si. 
St. 

St,  si. 
St,  sc. 

St. 
St. 
St. 
St. 
St. 
St. 

St. 

St. 

St,  sc. 
St. 

St,  si. 

St. 

St,  sc,  si. 


St,  sc. 
St. 
St,  sc. 

St,  si. 
St,  sc. 

St. 
Si. 
St,  sc. 


I  Abbreviations  of  seasons:  Sp,  spring;  Su,  summer;  Au,  autumn;  and  Wi,  winter. 

'  Abbreviations  of  sources:  St,  stomach  examination;  Sc,  scat  examination;  and  Si,  sight  record. 

303807° — 41 3 


28      NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 
Table  10. — Some  insect  foods  (68)  of  Attwater's  prairie  chicken 


Name 


Araneida: 

Spider  (Lycosidae) 

Spider  (undetermined) 

Orthoptera: 

Grasshopper  ( C jrrtacanthacrinae) 

Pigmy  locust  (Acrydinae) 

Grasshopper  {Syrbula) 

Grasshopper  (Oedipodinae) 

Western  grasshopper  (Melanoplus  ciner- 

eus). 
Green    grasshopper    (Chortophaga   viridi- 
fasciata) . 

Grasshopper  (Oedipodinae) 

Grasshopper  (Schistocerca  americana) 

Grasshopper  (Saliatoria) 

Meadow  grasshopper  (Conocephalus) 

Long-horned  grasshopper  (Tettigoniidae)  . 

Hemiptera: 

Shield  bug  (Pentatomidae) 

Bug  (undetermined  Hemiptera).. 

Stinkbug  (Euschisius) 

Homoptera: 

Leafhopper  (Cicadellidae) 

Lantern  fly  (Fulgoridae) 

Soft  scale  (Leucanium) 

Coleoptera: 

Weevil  (Oraphorhinus  vadosus) 

Weevil  (Lixus) 

Weevil  (Thecesternus  humeralis) 

Billbug  (Sphenophorus  minimus) 

Billbug  (Sphenophorus  bartramiae) 

Billbug  (Sphenophorus  germari) 

Billbug  (Sphenophorus) 

Weevil  (Paris) 

Weevil  (Hyperodes)  - 

Rice-water  weevil  (Lissorhoptrus  simplex) - 

Weevil  (Pachyphanes) 

Weevil  (Anthonomus  fulvus) 

Snout  beetle  (Curculionidae) 

Weevil  (Apian) 

Scarred  snout  beetle  ( Tanymecus  lacaena) . 
Scarred  snout  beetle  (Eudiagogus  pulcher) 
Scarred  snout  beetle  (Compsus  auricepha- 
lus). 

Leaf  beetle  (Phaedon  viridis) 

Leaf  beetle  ( Cryptocephalus  venustus) 

Leaf  beetle  ( Cryptocephalus) 

Leaf  beetle  (Zygogramma  disrupta) 

Leaf  beetle  (Oedionychis  petaurista) 

Leaf  beetle  (Metacroma  ustum) _. 

Leaf  beetle  (Disonycha) 

Leaf  beetle  (Ghrysomelidae) 

Leaf  beetle  (Calligrapha  similis) 

Leaf  beetle  (Oraphops  pubescens) 

12-spotted   cucumber   beetle    (Diabrotica 
duodecimpunctata) . 

May  beetle  (Phyllophaga) 

May  beetle  (Scarabaeidae) 

Leaf  chafer  (Anomala  ludotnciana) 

Dung  beetle  (Aphodius  sp.) 

Ground  beetle  (Triplectrus) 

Ground  beetle  (Eumolops) 

Ground  beetle  (Carabidae) 

Ground  beetle  (Chlaenius) 

Darkling  beetle  (Tenebrionidae) 

Lepidoptera: 

Moths,  butterflies,  and  skippers  (3  spe- 
cies) . 
Salt-marsh  caterpillar  (Estigmene  acraea).- 

Diptera: 

Gall  gnat  (Cecidomyiidae)... 

Robber  fly  (Asilus) 

Hymenoptera: 

Gall  fly  (Cynipidae) 

Chalcid  fly  (Chalcidae)... 

Paper  wasp  (Polistes) 

Ant  (Odontomachus  haemotodes) 

Ant  (Pheidole  sp) 

Fire  ant  (Solenopsis  sp.) 


Form  eaten 


Adult.. 
do- 


do 

Adult,  larva. 

do 

do 

do 


-do. 


.do. 


do_ 

do 

do 

Adult,  larva,  egg. 


Adult 

Adult,  eggs- 
Adult. , 


-do- 
.do-. 
-do- 

-do- 
-do- 
-do- 


-do- 
-do. 
.do. 
-do. 
.do. 
-do- 
.do. 
-do. 
.do. 
.do. 
.do. 


.do. 
.do. 
.do. 


.do. 


.do. 
.do. 
.do. 
.do. 
.do. 


-do. 
.do. 
.do. 
.do. 
.do. 


.do. 
.do. 
.do. 
-do- 


-do. 
.do. 
.do. 
.do. 
.do. 


Adult,  larva. 
....do 


Larva. 
Adult. 


Adult,  eggs.- 

Adult 

Adult,  pupa  cases. 
Adult 

do 


Seasons  when 
eaten  i 


Au-... 
Su,  au- 


Sp,  su 

Sp,  su,  au. 

Au :.. 

Au 

Su,  au 


Su. 


.do- 


Su 

Su 

Su 

Sp,  su,  au. 
Su,  au 


Sp- 
Su. 


Au,  wi,  sp- 
Sp,  su,  wi.. 
Au 


Wi,  sp- 
Su,  wi. 
Wi 


Sp,  au. 
Sp,  au. 
Su,  wi- 
Sp,  su.. 
Sp-.... 

Sp 

Sp_.... 
Sp.--.. 
Sp,  su.. 

Wi 

Wi 

Au 

Sp..... 


Wi 

Su,  au 

Su 

Su,  au 

Au 

Au 

Sp,  su,  wi. 
Sp,  su,  au. 

Wi 

Wi 

Wi 


Sp 

Su,  au 

Au 

Sp 

Au,  wi 

Wi 

Sp,  su.  au. 
Su--..— . 
Au... 


Su,  au. 
Su,  au. 


Sp. 
Au. 


Sp..... 

Su 

Su,  wi. 

Wi 

Su 

Su 


Source  of 
data' 


St. 
St. 

St,  sc. 
St,  sc. 
St. 
St. 
St,  sc. 

St. 

St,  sc. 
St. 
St. 
St. 
St,  sc. 

St. 
St. 
St,  sc. 

St. 
St. 
St,  sc. 

St. 

St. 

St. 

St. 

St,  sc. 

St,  sc. 

St,  sc. 

St. 

St. 

St. 

St. 

St. 

St,  sc. 

St. 

St. 

St,  sc. 

St. 

St. 

St,  sc. 

Sc. 

St,  sc. 

St. 

St. 

St,  sc. 

St,  sc. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St. 

St,  sc. 

Sc. 

Sc. 

Sc. 

Sc. 

St. 
St. 

St. 
Sc. 

St. 
St. 
St. 
St. 


'  See  footnote  1,  table  9. 
'  See  footnote  2,  table  9. 


ATTWATER'S   PRAIRIE    CHICKEN  29 

Native  plants  are  the  most  important  source  of  food  for  the 
prairie  chicken.  Rated  according  to  frequency  of  occurrence  in 
stomachs  and  scats,  gross  bulk,  and  periods  of  availability,  ruellia 
{Ruellia)  appears  to  be  by  far  the  most  important  single  food.  It 
occurred  in  13  of  the  18  stomachs  and  made  up  almost  27  percent 
of  all  the  material  eaten.  Stargrass  (^2/^6)a?^s),  bedstraw  {Galium)^ 
doveweed  (C^roi^o^i),  perennial  ragweed  {Ambrosia  psilostachy a)  also 
were  eaten  freely  through  long  seasons.  Practically  all  the  impor- 
tant food  plants  utilized  by  the  prairie  chicken  grow  naturally  in 
pastures  that  are  moderately  grazed.  Corn  was  the  only  cultivated 
grain  found,  and  the  small  quantity  present  was  probably  waste. 
It  is  known,  however,  that  prairie  chickens  are  fond  of  certain  crops, 
especially  peanuts,  hegari,  and  ripened  rice.  The  birds  frequently 
congregate  in  peanut  patches,  particularly  after  the  harvest,  and 
scratch  for  the  waste  pods.  They  also  use  conveniently  situated 
hegari  fields  extensively  in  summer,  but  the  good  shade  in  such 
areas  is  probably  as  attractive  as  the  grain.  Prairie  chickens  also 
range  into  rice  fields  after  the  crop  is  cut  and  shocked,  and  they 
sometimes  feed  on  the  grain  in  the  shock  as  well  as  on  that  so  freely 
wasted  on  the  ground  (pi.  7).  The  rice  taken  from  shocks  usually 
is  not  objectionable,  although  L.  D.  Roberts,  Eagle  Lake,  Tex., 
reports  that  he  saw  approximately  1,500  of  the  birds  feeding  in  a 
single  field  of  about  500  acres  in  the  Egypt  section,  Wliarton  County, 
in  September  1920.  By  scratching,  the  prairie  chickens  loosen  the 
shocks,  thus  allowing  moisture  to  seep  in,  and  this  causes  some  com- 
plaint. A  large  increase  of  prairie  chickens  might  conceivably  bring 
on  control  problems  in  certain  areas.  The  difficulties  would  prob- 
ably not  be  serious,  however,  because  the  birds  could  easily  be 
frightened  by  shotgun  fire  or  by  other  disturbances,  and  they  quickly 
desert  areas  of  potential  danger. 

Among  insect  foods  of  Attwater's  prairie  chicken,  11  grasshoppers 
(6  identified  to  genus  or  species)  are  especially  prominent;  32 
beetles  (identified  to  genus  or  species,  including  16  weevils)  also 
are  important.  The  vast  majority  (50  of  65)  of  the  insects  eaten 
by  prairie  chickens  are  kinds  neutral  (25)  or  harmful  (25)  to 
agriculture.  Field  observations,  and  reports  of  cooperators,  show 
that  prairie  chickens  eat  in  large  quantities  the  moths  of  the  cotton 
leaf  worm  {Alabafnu  argillacea),  one  of  the  worst  insect  pests  in 
the  coastal  area.  Under  ordinary  conditions,  the  food  habits  of 
Attwater's  prairie  chicken,  considering  both  insect  and  plant  con- 
sumption, are  such  as  to  make  it  one  of  the  most  valuable  birds  of 
farm  and  ranse. 


30      NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

HABITAT  REQUIREMENTS 
KIND  OF  HABITAT  BEST  SUITED 

The  coastal  prairie  grassland  is  the  real  home  of  Attwater's 
prairie  chicken,  particularly  in  areas  characterized  by  diversity  of 
vegetation  (pi.  8).  Woodland,  brushland,  and  cultivated  land  each 
furnish  some  food  and  cover  at  certain  times  and  under  certain 
conditions,  but  use  of  these  types  is  optional  with  the  prairie  chicken, 
not  vital.  These  secondary  habitats  are  frequented  mostly  when  food 
and  cover  are  at  the  annual  peak,  as  in  September  and  October, 
but  are  little  used  at  times  of  seasonal  scarcity,  as  in  December, 
January,  February,  and  early  in  March.  Wooded,  cultivated,  and 
brushy  areas,  individually  or  in  combination,  contribute  little  or 
nothing  as  courtship  grounds  and  nesting  cover.  Properly  managed 
grassland  (pi.  9),  however,  satisfies  every  known  requirement  of 
Attwater's  prairie  chicken,  and  management,  therefore,  should  be 
directed  toward  improvement  of  these  areas. 

CHARACTER  AND  DENSITY  OF  VEGETATION 

Optimum  food  and  cover  conditions  seemingly  are  approached 
when  the  prairie  vegetation  is  varied  in  species,  interspersion,  and 
density.  The  plant  life  of  well-populated  areas  includes  a  variety 
of  grasses,  sedges,  rushes,  and  legumes,  and  tall  weeds  or  their  cover 
equivalent  in  the  form  of  scattered  clumps  of  myrtle  or  live-oak 
brush.  The  combination  and  density  of  the  plants  in  the  most 
favored  places  invariably  is  such  as  to  provide  cover  in  all  degrees 
and  well  distributed. 

Light  cover  serves  (1)  exclusively  for  the  courtship  performance, 
(2)  for  feeding  at  all  seasons,  and  (3)  for  a  resort  when  dew  is 
heavy  or  after  rains.  Light  to  medium  heavy  cover  is  used  (1)  for 
roosting,  especially  on  gentle  slopes,  (2)  by  chicks  under  5  weeks  old, 
and  (3)  for  feeding  by  adults  throughout  the  year.  Cover  of  a 
medium  heavy  to  heavy  character  (pi.  9)  is  utilized  (1)  extensively 
for  nesting,  (2)  as  a  loafing  cover  except  during  the  hot  sunmier 
months,  and  (3)  as  feeding  grounds  and  escape  cover  in  emergencies. 
Heavy  cover  (pi.  9)  is  essential  (1)  for  shade  in  summer,  (2)  for 
protection  against  unfavorable  weather  and  predators  at  other  sea- 
sons, and  (3)  as  a  source  of  food,  especially  in  fall. 

TOPOGRAPHY 

Eichness  and  variety  in  the  vegetation  are  promoted  by  even  slight 
variations  in  topography  and  soil  (pi.  8).  Consequently,  the  best 
natural  range  for  Attwater's  prairie  chicken  comprises  country  in 
which  knolls,  ridges,  or  hog  wallows,  are  frequent.    Further,  knolls 


North  American  Fauna  57.  Fish  and  WildUfe  Service 


MMH 

^^■MMBB 

m^"'  '••"^'-^ 

.-»ii~.^.i*..  ■■ 

-m 

'■■.%-■.■     : 

J 

Above,  Diversified  cover^ — exceliont  i)rairie  chicken  range;  Colorado  County, 
Tex.,  approximately  7  miles  northeast  of  Eagle  Lake,  September  4,  1936. 
Below,  Diversity  of  topography  and  vegetation;  Austin  County,  Tex.,  approxi- 
mately 6  miles  northeast  of  Bellville,  June  13,  1936.  (Photos  by  V.  W.  Leh- 
mann.) 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


PLATE  9 


Above,  Medium-heavy  to  heavy  cover — excellent  food-cover  conditions  in  a 
moderately  grazed  pasture;  Colorado  County,  Tex.,  approximately  8  miles 
north  of  Eagle  Lake,  December  21,  1936.  Below,  Heavy  cover,  mostly  myrtle 
brush,  near  stream — excellent  summer  range;  Austin  County,  Tex.,  approxi- 
mately 4  miles  east  of  Bellville,  July  14,  1936.      (Photos  by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN  31 

and  ridges  are  least  likely  to  be  inundated  in  times  of  flood  and  they 
afford  the  birds  better  opportunity  of  eluding  their  natural  enemies 
and  man. 

WATER 

The  balanced  prairie  chicken  habitat  should  offer  a  generous  supply 
of  surface  water  throughout  the  year.  Although  Attwater's  prairie 
chickens  may  not  be  dependent  on  free  water  for  survival  during 
normal  years  (see  p.  23),  it  has  been  established  that  their  favorite 
summer  range  is  rather  well  watered.  During  unusually  dry  years 
such  as  occurred  in  Refugio  County  in  1917,  surface  water  may  be 
an  absolute  necessity.  Also,  through  its  effects  on  vegetation  and 
insect  life,  water  is  necessary  for  the  maintenance  of  optimum  cover 
and  food  conditions.  The  water  supply  of  prairie  chicken  areas 
apparently  is  about  optimum  when  permanent  sources  are  available 
throughout  the  range  at  intervals  not  greater  than  a  mile. 

Briefly,  then,  habitat  conditions  for  Attwater's  prairie  chickens 
seemingly  approach  the  ideal  in  grassland  area  when  (1)  the  vegeta- 
tion is  diversified  and  native  grasses,  sedges,  legumes,  and  small  and 
large  weeds,  or  their  equivalent  in  the  form  of  brush  or  dwarfed  trees, 
are  present  in  such  stands  as  to  provide  all  densities  of  cover;  (2) 
knolls,  ridges,  and  hog  wallows  are  frequent  and  the  soils  vary  from 
loose  sand  to  tight  clay  or  silt;  and  (3)  permanent  sources  of  surface 
water  are  available  not  more  than  a  mile  apart. 

SEASONS  OF  SCARCITY 

In  evaluating  the  suitability  of  an  area  for  Attwater's  prairie  chick- 
ens it  is  to  be  kept  in  mind  that  its  productivity  or  carrying  capacity 
is  not  determined  by  conditions  during  the  best  season  in  a  good  year. 
Rather,  as  Taylor  (1934)  states,  conditions  that  prevail  during  the 
most  critical  season  of  the  year  and  in  the  most  extreme  year  in  a 
series  of  years  determine  carrying  capacity.  In  the  coastal  country  of 
Texas  the  season  of  scarity,  or  the  period  when  food  and  cover  are  at 
a  minimum,  normally  is  from  December  through  early  March.  The 
most  critical  years  are  those  of  heavy  rainfall  in  May. 

LIMITING  FACTORS 

Factors  that  have  contributed  to  the  decrease  of  prairie  chickens 
in  Texas  may  be  classed  roughly  as  (1)  natural,  including  unfavor- 
able weather,  predators,  and  disease;  and  (2)  artificial,  including 
cultivation,  heavy  grazing,  burning,  and  overshooting.  It  might 
be  more  accurate  to  class  limiting  factors  as  those  brought  about  by 
man,  directly  or  indirectly.  Although  it  is  not  generally  appre- 
ciated, the  decrease  of  prairie  chickens  in  coastal  Texas  corresponds 


32       NORTH  AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

with  the  spread  of  civilization.  Prior  to  the  coming  of  white  men, 
the  number  of  birds  probably  was  well  maintained,  but  there  was 
a  decrease  as  the  country  was  developed.  Attwater's  prairie  chicken 
will  become  extinct  unless  man  ceases  to  exploit  the  soil,  water,  and 
other  natural  resources  of  its  range. 

NATURAL  FACTORS 

Rainfall  During  the  Nesting  Season 

Prairie  chickens  in  Texas  evidently  suffer  greatly  at  times  from 
extremes  of  weather.  Heavy  precipitation  during  the  nesting  and 
brooding  season  (March  through  June)  appears  to  be  an  especially 
serious  hazard,  as  indicated  by  the  studies  of  Waddell  and  others  in 
Colorado,  Austin,  and  AVliarton  Counties.  From  1925  through  1937 
Waddell  estimated  the  size  of  the  annual  crop  of  young  prairie 
chickens  on  the  basis  of  the  number  of  birds,  both  young  and  old 
(1)  observed  on  almost  daily  trips  through  their  range,  (2)  seen  by 
reliable  resident  observers,  (3)  bagged  by  hunters,  and  (4)  counted  an- 
nually on  the  courtship  grounds  in  spring.  From  his  studies  he  con- 
cluded that  crops  of  young  prairie  chickens  were  (1)  good  in  spring 
months  when  rainfall  was  below  average,  (2)  fair  to  good  when 
rainfall  was  average  or  only  slightly  above  average,  and  (3)  poor, 
very  few  young  being  reared,  when  the  nesting  season  was  abnormally 
wet. 

Waddell's  impressions  as  to  the  correlation  between  the  amount  of 
precipitation  in  spring  and  the  size  of  the  annual  crop  of  chickens 
were  tested  rather  thoroughly  in  1936  and  again  in  1937.  In  August 
1936,  after  a  reconnaissance  made  v/ith  car  and  dog  (see  p.  52)  over 
approximately  25,000  acres  of  territory  in  Colorado  and  Austin 
Counties,  it  was  estimated  that  the  annual  increase  was  less  than  10 
percent.  Rainfall  there  was  below  average  in  March,  April,  and 
June  1936,  but  it  exceeded  10  inches,  or  approximately  twice  the  aver- 
age, in  May,  as  shown  by  the  records  of  the  Weather  Bureau  at 
Columbus,  situated  centrally  in  that  area.  In  1937,  when  records 
of  this  station  showed  that  rainfall  was  2  inches  or  more  below 
average  in  April,  May,  and  June,  rope  counts  made  of  3,450  acres 
both  before  and  after  the  breeding  season  revealed  a  95-percent  in- 
crease, supporting  Waddell's  estimate  that  the  increase  was  good 
in  a  dry  season. 

In  table  11,  p.  33,  Waddell's  estimates  of  the  favorableness  of  the 
years  from  1925  through  1937  for  prairie  chicken  reproduction  are 
presented  together  with  precipitation  records  of  the  Columbus 
Weather  Bureau  Station  for  March,  April,  May,  and  June  in  those 
years. 


ATTWATER'S    PRAIRIE    CHICKEN 


33 


Table  11.— Reproductive  yield  of  Attwater's  prairie  chicken  in  relation  to  spring 
rainfall  in  inches  ^  in  the  Colorado  County  area  ^ 


Estimated 
yield 

March 

April 

May 

June 

Year 

Precip- 
itation 

Depart- 
ure 
from 

normal 

Precip- 
itation 

Depart- 
ure 
from 

normal 

Precip- 
itation 

Depart- 
ure 
from 

normal 

Precip- 
itation 

Depart- 
ure 
from 

normal 

1925 

1926 

Good 

Fair       .    . 

0.33 
11.54 
3.49 
1.42 
4.54 
2.34 
3.84 
3.63 
2.36 
3.91 
3.72 
1.23 
6.01 

-2.50 

-8.71 

.66 

-1.41 

1.71 

-.49 

1.01 

.80 

-.47 

1.08 

.89 

-1.60 

3.15 

0.99 
7.86 
4.00 
3.76 
2.58 

.48 
1.43 
2.19 
1.43 
4.28 
4.58 
3.48 

.52 

-2.74 

4.13 

.27 

.03 

-1.15 

-3.25 

-2.30 

-1.54 

-2.30 

.55 

.85 

-.25 

-3.21 

2.87 
4.10 
1.24 
2.00 

16.12 
3.11 
1.98 
.66 
3.67 
1.90 
9.21 

10.65 
.47 

-1.51 

-.28 

-3.14 

-2.38 

11.74 

1.27 

-2.40 

-3.72 

-.71 

-2.48 

4.83 

6.27 

-3.91 

1.06 
3.37 
6.43 

8.52 
.99 
.89 
.90 

3.68 

1.40 
.22 

2.48 
.79 

1.37 

-2.12 
19 

1927 

1928 

1929 - 

1930 

Good 

do 

Poor 

Fair 

3.25 

5.34 

-2.19 

—  2  29 

1931      

Good 

do 

Fair 

—  2.28 

1932 

1933 

.50 
-1.78 

1934 

Good- - 

Poor 

___.  do 

—  2.96 

1935       

-.70 

1936      

—  2.39 

1937 

Good 

-1.81 

1  Records  of  U.  S.  Weather  Bureau  Station,  Columbus,  Colorado  County. 

'  Colorado  County,  north  central  Wharton  County,  southwestern  Austin  Coimty. 

Waddell  found  good  crops  of  young  birds  in  the  Eagle  Lake  area 
in  1925,  1927,  1928,  1931,  1932,  1934,  and  1937,  years  when  rainfall 
in  May  was  1.5  inches  or  more  below  average.  Fair  crops  of  young 
prairie  chickens  were  thought  to  have  been  reared  in  1926,  1930, 
and  1933,  when  rainfall  in  May  was  approximately  average  (0.28 
below  in  1926)  to  only  slightly  above  (1.27  above  in  1930).  Poor 
crops  were  matured  in  1929,  1935,  and  1936,  when  May  precipitation 
was  appreciably  above  (approximately  twice)  the  average  for  that 
month.  Unusually  heavy  or  light  precipitation  in  March,  April,  or 
June  evidently  liad  little  influence  on  the  broods  of  young,  for  good 
crops  were  recorded  in  1927,  when  rainfall  was  decidedly  above 
average  in  June,  and  a  poor  crop  is  known  to  have  occurred  in  1936, 
w^hen  rainfall  was  below  average  in  all  months  of  the  nesting  season 
except  May.  The  records  at  hand  suggest,  therefore,  that  the  rain- 
fall in  May  is  a  fairly  satisfactory  index  of  the  suitability  of  the 
year  for  the  reproduction  of  Attwater's  prairie  chicken  under  natural 
conditions.  Good  crops  usually  result  when  the  rainfall  in  May  is 
1.5  inches  or  so  below  average ;  fair  crops  are  probable  when  it  is 
approximately  average  or  only  slightly  above;  and  poor  crops  appear 
almost  a  certainty  when  the  rainfall  for  that  month  is  decidedly 
above  average. 

Rainfall  in  May  is  of  greater  significance  than  that  in  any  other 
month,  as  the  1937  and  1938  nesting  studies  showed  that  most  of  the 
chicks  hatch  in  May.  Those  hatched  in  April  do  not  yet  have  a 
serviceable  covering  of  feathers  by  May  and,  consequently,  are  almost 
as  vulnerable  to  the  rains  as  are  birds  hatched  in  that  month.  Nests 
flooded  in  March  and  April  may  be  rebuilt,  for  the  booming  season 
is  still  in  full  swing,  but  nests  flooded  after  May  1  are  seldom  re- 


34       NORTH   AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

established  because  the  mating  season  is  then  nearly  over.  May,  then, 
is  the  climax,  or  peak  month,  of  the  breeding  season,  and  rainfall 
then  is  of  greater  significance  than  at  any  other  period. 

The  nature  of  rains  in  May  may  be  a  factor  modifying  the  use  of 
precipitation  records  for  that  month  as  indices  of  the  number  of 
chicks  produced,  as  short,  heavy  downpours  may  be  more  serious  than 
slow  steady  rains.  This,  however,  is  not  known  to  be  true.  Fre- 
quently recurring  light  rains  may  be  as  serious  as  heavy  ones  be- 
cause persistent  damp  conditions  result  in  heavy  juvenile  mortality 
from  chilling.  Stoddard  (1931:  39,  202)  shows  that  wet  spring 
months  are  favorable  for  hatching  but  not  for  rearing  bobwhites. 
Percolation  and  drainage  are  slow  in  the  heavy  coastal  prairie  soil, 
and  surface  moisture  accumulates  from  persistent  light  rains  as  surely 
as  from  brief  heavy  ones ;  the  amount  rather  than  the  severity  of  the 
rain  seems  to  rule. 

While  it  is  realized  that  annual  precipitation,  drainage,  cover,  and 
other  environmental  conditions  in  Colorado  County  are  not  identical 
with  those  obtaining  throughout  the  coastal  prairie  chicken  country, 
a  marked  similarity  does,  nevertheless,  exist.  Rainfall  is  moderately 
heavy,  39  inches  annually,  at  Columbus,  Colorado  County,  and  it  is 
also  generous  throughout  the  bird's  range.  Average  annual  precipi- 
tation varies  from  49.35  inches  at  Beaumont,  Jefferson  County,  to 
33.69  inches  at  Austwell,  Refugio  County,  at  about  the  eastern  and 
western  limits,  respectively,  of  the  subspecies.  Rainfall  during  May 
at  Columbus  (average,  4.38  inches)  is  heavier  than  in  any  other 
month.  May  is  the  wettest  month  in  Jackson,  Goliad,  Lavaca,  and 
Harris  Counties  as  well.  Heavy  or  persistent  rains  transform  tre- 
mendous areas  in  Colorado  Coimty  into  veritable  lakes  ranging  from 
a  few  inches  to  several  feet  in  depth;  rains  produce  similar  results 
throughout  the  coastal  region.  It  appears  justifiable,  therefore,  to 
assume  that  rainfall  in  May  is  the  key  to  prairie  chicken  reproduc- 
tion throughout  coastal  Texas  (fig.  3) . 

Of  every  5  years  in  a  given  locality,  apparently  2  are  favorable 
for  nesting,  2  fair  to  poor,  and  1  bad,  as  determined  by  rainfall  in 
May.  Conditions  are  never  uniform  in  the  chicken  country  ag  a 
whole  because  there  is  variation  between  counties  and  even  between 
parts  of  the  same  county.  Records  of  the  Weather  Bureau  for  May 
1935  show,  for  example,  that  rainfall  at  Galveston,  Galveston  County, 
was  favorable  (2.71  inches  below  average) ;  at  Houston,  Harris 
County,  fair  (only  0.20  inch  below)  ;  and  that  at  Columbus,  Colorado 
County,  poor,  being  approximately  twice  average  (4.83  inches  above) . 
During  1926  in  Brazoria  County  conditions  were  good  at  Alvin,  fair 
at  Angleton  and  Freeport,  and  poor  at  Brazoria.  In  1932  conditions 
were  good  at  Angleton,  fair  at  Freeport,  and  poor  at  Alvin.  Though 
man  cannot  regulate  rainfall  to  promote  prairie  chicken  welfare 


I  57.  Fith  «nd  WUdJife  Strvice 


LEGEND 

Rainfall  1 .50  inches  or  more  below  average  _____ 

Rainfall  1 .49  below  average  to  1 .99  above  average 

Ramfall  2  inchea  or  more  above  average,  but  less  than  twice  aver 
Rainfall  twice  average  or  more 

Compilations  based  on  records  of  average  annual  May  rainfall  i 
supplied  by  the  Climatological  Division.  U.  S.  Weather  Bure 
Records  missing  or  unsatisfactory 


-I — i(G°°a) 

Erg  (Fair) 

.  ^  (Bad) 


ich  individual  station 


CZ] 


Rainfall  conditions  in  May  in  the  range  of  Attwatcr's  prairie  chicken  in  Texas,  in  the  66  years  I87I  to  1936. 
indicating  the  probable  frequency  of  good  and  other  reproductive  years  for  the  birds 


ATTWATER'S   PRAIRIE    CHICKEN  35 

at  nesting  and  brooding  time,  in  many  case3  he  can  regulate  pasture 
burning  and  grazing  to  provide  adequate  nesting  cover  in  the  best- 
drained  parts  of  the  land.  Also,  he  can  consult  weather  records 
before  setting  open  seasons  and  bag  limits,  which  should  not  be 
uniformly  applied  but  adjusted  to  local  conditions  to  preserve  the 
birds. 

Floods 

Flood  conditions  are  often  produced  by  heavy  rains  in  the  over- 
grazed and  overfarmed  sections  in  the  upper  part  of  the  State. 
Heavily  burdened  streams  carrying  flood  crests  from  the  upper  coun- 
try sometimes  spill  over  their  low  banks  and  spread  their  silt-laden 
waters  over  thousands  of  acres  of  prairie  chicken  range.  This  oc- 
curred in  the  Rock  Island-Garwood  section  (Colorado  County)  in 
June  1936,  when  the  prairie  chicken  population  of  that  section  was 
extirpated.  Floods  evidently  are  a  constant  menace  to  birds  near 
major  streams. 

Dbought 

Extreme  drought  seriously  affects  prairie  chickens,  especially  dur- 
ing the  hot  summer  months.  G.  P.  Ferguson,  State  game  warden, 
and  fence  riders  on  the  M.  O'Conner  ranch,  Refugio  County,  found 
many  dead  birds  in  the  especially  dry  suimner  of  1917  and  saw  others 
too  weak  to  fly.  Drought  reduces  food  supplies  for  both  present  and 
future  use.  Large  cracks  that  form  in  black  soil  in  dry  weather  pos- 
sibly trap  some  young  birds,  according  to  the  observations  of  Gross 
(Bent  1932:  253).  Birds  weakened  by  excessive  heat,  and  possibly 
also  by  a  shortage  of  food,  are  especially  vulnerable  to  disease,  pred- 
ators, adverse  weather,  and  other  hazards. 

HXJBBICANES 

Tropical  hurricanes  sometimes  produce  flood  conditions  in  prairie 
chicken  country  20  miles  or  more  from  the  Gulf.  In  1917  a  storm 
backed  salt  water  over  the  greater  part  of  the  Pipkin  ranch  in  the 
Big  Hill  area  in  Jefferson  County  and  drowned  livestock  by  the 
hundreds.  That  it  evidently  destroyed  many  prairie  chickens  as 
well  was  indicated  by  their  exceeding  scarcity  for  15  years  afterwards. 

TTatt. 

Heavy  hail  storms  destroy  many  Attwater's  prairie  chickens,  es- 
pecially in  areas  where  heavy  protective  cover  is  lacking.  After  a 
storm  in  May  1934,  J,  O.  Linney,  Guy  Ferguson,  and  fence  riders  on 
the  Salt  Creek  ranch,  Refugio  County,  saw  about  150  dead  or  crippled 
chickens. 


36       NORTH  AMERICAN  FAUNA  5  7,  FISH  AND  WILDLIFE  SERVICE 

Local  Storms 

Local  storms,  especially  those  that  commonly  occur  in  fall,  kill 
turkeys  and  other  domestic  fowls  and  prairie  chickens  and  other  game 
birds,  as  reported  by  Marcus  Shindler,  Ed  Koy,  and  other  resident 
land-owners  in  the  northeastern  part  of  Colorado  County. 

Disease 

Gross  (1930a:  39),  and  Stoddard,  Curtis,  Lews,  Terrel,  and  others 
(Leopold  1931:  182-183),  recorded  incidents  strongly  suggesting  that 
disease  and  parasites  probably  were  important  controlling  factors  on 
the  abundance  of  the  greater  prairie  chicken  of  the  Northern  States. 
Records  at  hand  do  not  show  that,  in  the  past,  disease  has  been  a  factor 
of  importance  limiting  the  numbers  of  Attwater's  prairie  chicken  in 
Texas.  The  observations,  mentioned  above,  made  by  G.  P.  Ferguson 
on  the  M.  O'Conner  ranch  furnished  the  only  known  evidence  even 
faintly  suggesting  an  outbreak  of  disease.  In  that  instance,  however, 
it  is  probable  that  mortality,  if  really  due  to  disease  or  parasites,  was 
an  indirect  result  of  prolonged  drought.  No  evidence  of  disease  or 
heavy  parasitism  was  found  in  autopsies  made  on  13  prairie  chickens, 
and  no  evidence  of  any  unhealthful  condition  was  observed  among 
hundreds  of  birds  in  the  field.  Prairie  chickens  are  doubtless  sus- 
ceptible, however,  to  ailments  of  domestic  poultry.  An  outbreak  of 
blackhead  disease,  probably  contracted  from  domestic  turkeys,  is  con- 
sidered by  Gross  (Bent  1932:  268)  as  a  major  factor  in  the  extermina- 
tion of  the  heath-hen.  Turkeys  and  other  poultry,  therefore,  probably 
are  unhealthful  influences  on  a  prairie  chicken  range. 

Spkeab  of  Woody  Vegetation 

The  encroachment  of  mesquite,  live  oak,  various  acacias,  and  other 
kinds  of  brush  onto  open  prairie  land  has  been  an  extremely  impor- 
tant factor  in  reducing  the  range  and  doubtless  the  numbers  of  Att- 
water's prairie  chickens  in  Refugio  and  other  counties  to  the  south 
and  west.  Within  the  memory  of  living  men  extensive  prairies  have 
been  transformed  into  brush  jungles.  Specific  factors  that  have  in- 
fluenced the  rapid  vegetational  changes  in  the  southwestern  brush 
country  are  imperfectly  understood.  Factors  probably  of  importance 
in  enabling  woody  plants  to  replace  the  native  grassland  flora  have 
been  overgrazing,  especially  during  drought  years;  the  mechanical 
planting  of  tree  seeds  by  cattle  and  horses,  because  livestock  eat  large 
quantities  of  mesquite  and  other  beans,  the  seeds  of  which  pass  through 
the  digestive  tract  and  are  distributed  or  planted  by  the  droppings ; 
the  elimination  of  burning,  previously  mentioned  by  Bray  (1901: 
288-290)  and  Tharp  (1926:  71)  ;  and  the  lowering  of  the  water  table. 
Be  that  as  it  may,  hundreds  of  thousands  of  acres  of  what  was  once 


ATTWATER'S    PRAIRIE    CHICKEN 


37 


tall-grass  prairie  are  now  brushland,  and  prairie  chickens  are  gone 
from  these  areas. 

Pkedation 


NESTS 


Natural  enemies  consume  some  of  the  eggs,  young,  and  adults  of 
Attwater's  prairie  chicken.  The  extent  of  predation  on  nests  and  the 
identity  of  other  factors  responsible  for  nest  loss  in  the  Eagle  Lake 
area  are  given  in  tables  12  and  13. 

Table  12. — Fate  of  nests,  Eagle  Lake,  Colorado,  1937 


Nest 
No. 

Pasture 

Date 
found 

Date 

destroyed 

or 
hatched 

Probable  cause  of  destruction 

1    ... 

Everett 

Apr.     7 

Apr.     8 
Apr.   12 

---do...- 
Apr.   13 
Apr.  21 

-...do..-. 

---do.... 
Apr.  27 
Apr.  29 
May    1 

May  11 
June    1 

Apr.   22 

Apr.    4  3 
Apr.     7 
Apr.   13 
May  17 
Apr.   15 
Apr.  21 
Apr.   18 
May    4 
May  15 
May    2 

Apr.     6 
June    2 

or 
June    3 

Man— nest  deserted  after  entrance  was  widened 
by  a  farmer. 

21 

do 

31 

Wintermann    .- 

Opossum  or  skunk. 

Skunk. 

Hatched  successfully. 

Skunk. 

i 

6.. - 

do 

Sklar-Marcella 

Wintermann 

61 

71 

81. 

9 

do 

do 

Duncan... 

Do. 
Deserted,  cause  unknown. 
Hatched  successfully. 

Do 

10 

Everett  . 

H 

Willis 

Man— nest  deserted  after  farmer  plowed  territory- 
nearby  and  revisited  nest  frequently. 
Opossum. 
Hatched  successfully. 

12».. 

13    .    - 

Sklar-Marcella 

do 

1  Nest  destroyed  when  found. 

'  Estimated  in  case  of  nests  destroyed  when  found. 

» Indicated  by  circumstantial  evidence  at  the  nest. 

Table  13. — Fate  of  nests,  Eagle  Lake,  Colorado  County,  Tex.  (1938) 


Nest  No. 

Pasture 

Date 
found 

Date  de- 
stroyed 

or 
hatched 

May    3 
Apr.  23 
Apr.  29 
May    3 
May  11 
June  21 

Probable  cause  of 
destruction  i 

14 

Sen 

Apr.   13 

Apr.   18 

do 

15 

Thomas 

House  cat 

16    

do 

Hatched  successfully. 

17 

do 

Apr.  29 
Apr.  20 
June    3 

18 

Everett  

19     

....  do 

Hatched  successfully. 

1  Indicated  by  circumstantial  evidence  at  nest. 

Of  19  prairie  chicken  nests  studied  in  1937  and  1938,  6  (31.5 
percent)  were  successful,  and  13  (68.4  percent)  were  lost.  In  1937 
8  of  13  nests  studied  were  destroyed  before  the  clutches  were  com- 
plete, showing  that  the  laying  period  may  be  the  one  of  heaviest 
nest  loss.  This  might  be  expected,  as  the  eggs  are  covered  only  about 
an  hour  or  so  each  day  during  that  time.  This  loss  is  somewhat 
compensated,  however,  by  renesting  (see  p.  15).  Opossums  and 
skunks  destroyed  6  nests — more  than  any  other  agency.     Of  the  6, 


38       NORTH   AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

however,  4  were  in  a  pasture  where  unregulated  fire  had  restricted 
good  nesting  cover  to  2  small  unburned  areas  about  3  and  10  acres 
in  size.  Fur  animals  as  well  as  nesting  chickens  were  unnaturally 
concentrated  in  these  unburned  plots;  dens  containing  young  were 
100  yards  or  less  from  each  of  the  nests  destroyed.  Excessive  pas- 
ture burning  appeared  to  be  the  primary  cause  of  the  heavy  nest 
loss ;  predation  by  fur  animals  being  merely  an  effect,  the  agency  of 
destruction  that  was  inevitable  after  the  burning. 

Field  evidence  showed  that  a  red  wolf  killed  a  female  prairie 
chicken  and  destroyed  her  nest;  a  feral  house  cat  devoured  the 
eggs  from  another  nest  (pi.  10).  It  is  surprising  that  dogs  did 
not  figure  as  predators  on  the  nests  and  that  house  cats  did  not 
take  an  even  greater  number.  Wandering  dogs,  usually  in  groups  of 
three  to  five,  were  not  uncommon  on  Colorado  County  prairies;  L. 
A.  Burchfield,  a  trapper  who  worked  for  the  former  Bureau  of 
Biological  Survey  in  Colorado  County  in  1937,  and  Waddell  found 
that  dogs  did  much  of  the  damage  for  which  the  few  red  wolves, 
now  largely  extirpated  in  the  area,  were  blamed.  Heavy  predation 
on  a  flock  of  domestic  turkeys,  supposedly  by  wolves,  stopped  imme- 
diately when  a  hound,  which  frequently  hunted  on  its  own  initiative, 
was  killed  after  having  been  caught  in  a  trap  set  for  the  alleged 
wolves.  Feral  house  cats  on  Colorado  County  prairies  probably 
outnumber  skunks,  opossums,  minks,  or  any  other  fur  animals.  Cot- 
ton rats  and  other  rodents  were  common  near  several  nests  but  took 
no  eggs.  Neither  did  racers,  chicken  snakes,  king  snakes,  or  other 
reptiles  frequently  noted  after  May  1  in  both  1937  and  1938. 

Three  nests  were  abandoned,  desertion  of  two  of  these,  possibly 
all  three,  being  caused  by  man.  Nesting!  prairie  chickens  seem 
especially  sensitive  to  interference,  and  they  should  not  be  dis- 
turbed by  persons  making  repeated  visits.  Of  six  nests  under  obser- 
vation in  1938,  floods  destroyed  two,  and  accumulated  water  from 
heavy  rains  came  within  V^  feet  of  a  third  (nest  16).  The  following 
excerpt  from  the  writer's  field  notes  of  May  3,  1938,  emphasizes  the 
importance  of  floods : 

The  prairie  has  been  transformed  into  a  miniature  ocean  dotted  by  tiny 
islands  that  previously  had  been  the  tops  of  knolls  and  ridges.  On  these 
islands  sit  wet  and  bedraggled  prairie  chickens  and  other  birds  that  seem  as 
confused  and  astounded  as  I  by  the  sudden  change  in  their  environment.  About 
a  5-inch  depth  of  water  covers  the  sites  of  nests  14  and  17,  and  former 
nest  15.  Nest  16  has  escaped  by  a  hair's  breadth,  but  the  lining  is  very  soggy. 
Problems  due  to  hawks,  skunks,  and  other  predators  seem  so  petty  when  exces- 
sive rain  destroys  virtually  everything  at  a  single  stroke. 


Although  predators  doubtless  exert  great  pressure  on  the  popula- 
tion of  young  prairie  chickens  in  some  areas,  especially  because  the 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


Plate  10 


;   646862 


AboDc,  Shells  of  eggs  at  prairie  chicken  nest  destroyed  by  house  cat;  Colorado 
County,  Tex.,  approximately  5  miles  north  of  Eagle  Lake,  April  23,  1938. 
(Photo  by  Texas  Game,  Fish,  and  Oyster  Commission;  E.  P.  Haddon.)  Below, 
Freshly  killed  prairie  chicken  recovered  from  a  ferruginous  rough-legged  hawk; 
Colorado  County,  Tex.,  approximately  6  miles  north  of  Eagle  Lake,  April  7, 
1937.      (Photo  by  V.  W.  Lehmann.) 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


PLATE    1  1 


B49777A,    £60058 


Above,  Native  bluestem  prairie — well  populated  b}'  prairie  chickens:  Colorado 
County,  Tex.,  6  miles  northeast  of  Eagle  Lake,  December  21,  1936.  Below, 
Prairie  after  plowing  for  rice — deserted  by  prairie  chickens;  Colorado  County, 
Tex.,  approximately  5  miles  north  of  Eagle  Lake,  March  7,  1938.  (Photos 
by  V.  W.  Lehmann.) 


ATTWATER'S  PRAIRIE    CHICKEN  39 

loose  formation  of  the  brood  (see  p.  19)  and  straying  apparently 
induce  mortality  from  this  cause,  definite  information  was  difficult 
to  obtain. 

A  female  Krider's  hawk  caught  a  third-grown  prairie  chicken  on 
May  24,  1937.  From  then  on  until  June  9,  when  the  male  was  col- 
lected, this  hawk,  assisted  by  her  mate,  hunted  a  section  containing 
six  broods.  Most  migrant  raptors  (roughlegs,  redtails,  and  marsh 
and  duck  hawks)  had  left  Colorado  County  prior  to  May  1,  1937,  and 
April  15,  1938,  before  many  young  had  hatched,  and  the  resident 
species  (red-shouldered,  Cooper's,  Sennett's  white- tailed,  and  Krider's 
hawks)  confined  their  activities  largely  to  wooded  areas.  Because 
cover  is  dense  in  summer,  and  hawks  are  then  uncommon,  probably 
few  young  prairie  chickens  are  taken  in  normal  years. 

House  cats  with  freshly  killed  young  prairie  chickens  were  noted 
twice  in  1937  and  were  seen  stalking  broods  on  three  other  occasions. 
Because  of  their  numbers  and  predilections,  house  cats  are  thought 
to  be  exceedingly  destructive. 

ADULTS 

Prairie  chickens  on  the  courtship  grounds  seemed  more  intent 
on  mating  than  on  self-preservation ;  consequently,  losses  from  preda- 
tion  were  probably  heaviest  at  mating  time.  In  Colorado  County, 
during  most  of  the  1937  and  1938  courtship  seasons  the  abundant 
hawks  harassed  the  prairie  chickens  persistently,  sometimes  with 
success.  On  April  8,  1937,  3  duck  hawks,  7  marsh  hawks,  2  rough- 
legs,  3  Krider's  hawks,  and  2  bald  eagles  kept  the  chicken  population 
(about  45  birds)  of  the  Everett  pasture  (640  acres)  constantly  mov- 
ing. A  freshly  killed  male  prairie  chicken  (pi.  10)  was  taken  from 
a  ferruginous  roughleg  in  that  area  on  April  17.  Marsh  hawks, 
which  Stoddard  and  others  have  found  to  be  sometimes  more  bene- 
ficial than  harmful  to  quail  and  other  game,  were  especially  an- 
noying to  courting  birds,  no  other  factor  interfering  with  their 
activities  to  so  great  an  extent.  Wlien  a  marsh  hawk  darted  at 
one  occupant  of  the  booming  ground,  others  generally  cowered.  The 
hawks  pursued  their  intended  victims  for  short  distances,  but  soon 
returned  and  flushed  others,  or  after  dispersing  the  grouse,  fre- 
quently alighted  on  the  courtship  grounds  to  await  their  return  and 
resume  the  flushing  tactics.  On  April  8,  1937,  4  marsh  hawks  con- 
centrated on  a  single  courtship  ground  and  harassed  the  6  male 
occupants  from  5  to  7 :30  p.  m.  Although  no  birds  were  killed,  one 
lost  many  feathers  when  two  hawks  dived  at  it  simultaneously. 

By  flushing  prairie  chickens,  marsh  hawks  render  them  vulnerable 
to  more  efficient  winged  enemies,  as  duck  hawks,  goshawks,  and  the 
like.  Waddell  has  seen  duck  hawks  catch  adult  chickens  on  at 
least  two  occasions. 


40       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

Mammals  also  take  some  of  the  birds  on  courtship  areas.  The 
stomach  of  a  male  house  cat  collected  April  12,  1937,  near  a  booming 
ground  in  the  Everett  pasture,  Colorado  County,  contained  the  head, 
feet,  and  part  of  the  breast  of  a  freshly  killed  male  prairie  chicken. 
The  remainder  was  found  about  50  feet  away. 

A  red  wolf  was  suspected  of  killing  a  female  prairie  chicken  on 
the  nest,  and  either  red  wolves  or  dogs  took  three  others  in  Colorado 
County  in  April  1937. 

Only  six  instances  of  adult  mortality  were  discovered  that  year, 
although  intensive  search  for  remains  was  made  on  foot  and  in  cars 
over  approximately  2,500  acres.  In  1938,  when  none  of  the  pastures 
were  burned,  no  dead  birds  were  found. 

Review  of  Natueai,  Factoes 

Natural  factors  limit  the  abundance  of  prairie  chickens  by  destroying 
eggs,  young,  and  adults  and  by  reducing  favorable  territory.  During 
the  breeding  season  floods,  storms,  hail,  drought,  and  excessive  or  per- 
sistent rains  are  known  to  be  locally  serious,  the  rains  in  May  being  most 
damaging.  Drought  has  been  associated  with  the  only  reported  out- 
break of  disease  that  occurred  in  the  Refugio  area  in  1917.  The  en- 
croachment of  brush  on  prairie  land  has  transformed  thousands  of  acres 
of  what  was  once  good  prairie  chicken  range  (pi.  11)  into  an  unfavorable 
habitat.  Although  some  predators  harass  the  birds  throughout  the 
year,  their  effects  are  probably  most  serious  at  mating  and  nesting 
time.  Natural  mortality  from  climate  and  predators  is  severe  in 
inferior  or  isolated  cover. 

The  serious  effects  of  natural  factors  are  in  every  case  either  brought 
about  or  intensified  by  man's  generally  unwise  treatment  of  natural 
factors.  All  except  feral  house  cats  and  predatory  dogs  were  operat- 
ing against  the  prairie  chickens,  apparently  without  disastrous  results, 
before  the  environment  was  radically  modified  by  man.  Since  the 
unfavorable  influences  of  natural  agencies  are  due  chiefly  to  man,  it 
is  encouraging  to  know  that  it  is  within  his  power  and  often  decidedly 
advantageous  to  him  so  to  modify  his  actions  as  to  improve  existing 
conditions  and  promote  the  welfare  of  the  prairie  chickens  as  well  as 
his  own. 

ARTIFICIAL  FACTORS 

Agriculture 

Much  of  the  best  prairie  chicken  range  has  been  recently  appro- 
priated for  agricultural  uses.  More  than  2,000,000  acres  (table  14) 
were  cultivated  in  1936.  In  addition,  thousands  of  acres  of  sod  are 
plowed  annually,  with  the  extension  of  agriculture,  especially  rice 
farming.     The  acreage  yearly  planted  to  rice  in  coastal  Texas  in- 


ATTWATER'S   PRAIRIE    CHICKEN 


41 


creased  from  approximately  174,500  acres  in  1922  to  more  than  196,500 
acres  in  1937.^  This  latter  acreage  represents  only  a  small  part  of  the 
area  actually  depleted:  rice  farming  has  ruined  more  than  84,000 
acres  for  the  birds  in  Colorado  County  (pi.  11)  alone,  and  probably 
in  excess  of  a  million  acres  in  the  State  as  a  whole.  Rice  is  hard  on 
the  land  and  most  areas  devoted  to  it  can  be  profitably  cultivated 
during  only  about  1  year  in  4,  after  which  they  must  be  left  fallow  for 
about  3  years  to  "sweeten."  Weedy  rice  fields  ostensibly  provide  satis- 
factory grouse  range ;  actually,  however,  they  lack  suitable  courtship 
grounds  and  safe  nesting  cover,  and,  furthermore,  the  levees  collect 
water  that  floods  nests.  Prairie  chickens  in  fallow  rice  land  ap- 
parently are  doomed  even  though  they  are  hunted  lightly  or  not  at 
all.  According  to  Waddell,  there  were  10,000  of  the  birds  on  30,000 
acres  of  the  Egypt  section,  Wharton  Comity,  in  1924.  Rice  farming 
began  there  in  1925,  and  by  1937  all  the  30,000  acres  were  either  in 
cultivation  or  fallow.  Hunting  pressure  was  reduced  annually  after 
1925,  and  few,  if  any,  birds  were  killed  after  1935.  In  1938,  however, 
less  than  150  prairie  chickens  remained.  Prairie  chicken  decrease  was 
also  positively  correlated  with  the  expansion  of  rice  farming  in  eastern 
Chambers  and  central  Matagorda  Counties.  As  additional  acres  of 
prairie  are  plowed,  further  decreases  are  certain  to  follow. 


Table  14. — Harvested  and  other  crop  land  (1936)  in  counties  partially  or  en- 
tirely loithin  the  probable  former  range  of  Attwater's  prairie  chicken  in 
Texas ^ 


County 

Harvested 
crop  land 

Other 
crop  land 

Total 
crop  land 

County 

Harvested 
crop  land 

Other 
crop  land 

Total 
crop  land 

Aransas.. 

Acres 

2,484 
105.  396 

92,  247 
98,045 
34,  425 

130,  684 
16,  772 

93,  562 
153,  307 
176,  495 

19,  848 
64,  374 
100,  263 
82,  609 
44,205 

Acres 
1,772 
11,313 
20,  685 
17,  787 
12.  5S0 
32,  483 
5,727 
11,03.S 
30, 843 
41,  793 
3,  396 
12,711 
25,  031 
15,  114 
12,  386 

Acres 

4,256 
116,  709 
112,932 
115, 832 
47,005 
163, 167 
22,499 
104,  600 
184, 150 
218,  288 
23,244 
77, 085 
125,  294 
97,  723 
56,  591 

Kenedy 

Acres 

204 

28,639 

158,  604 

47,704 

.59,  714 

228,  609 

8,  245 

40, 147 

165,  691 

100,  300 

47,  986 

187,  555 

60,  981 

Acres 

Acres 
204 

Austin 

7,211 
10,  652 
12,  836 

21,  952 
62, 090 

1,334 
16, 183 
35,  769 
17,828 
10,  040 

22,  909 
10, 001 

35,  850 
169,  256 

Bee    

Brazoria 

Calhoun  . 

Matagorda.. 

Nuoc^s. 

81,  666 
290  699 

Cameron 

Chambers 

Orange..' 

9  579 

Colorado -_ 

56,  330 
201  460 

DeWitt    

San  Patricio 

Victoria    

Fort  Bend 

118,'  128 

Galveston 

Waller             

58  026 

Goliad 

210  464 

Harris 

Willacy       ..    . 

70,  982 

Total 

2, 349, 095 

483,464 

2, 832,  559 

>  Data  from  Texas  Almanac  and  State  Industrial  Guide,  pp.  231-236,  The  Dallas  News,  1936. 

Pastubh  Bubninq 

Unregulated  prairie  fires  intentionally  set  or  of  accidental  origin 
have  been,  and  still  are,  common  in  coastal  Texas  in  every  month  of 


^  Figures  supplied  by  David  WinternLinn,  Relow  Land  Company,  Eagle  Lake,  Tex.,  from 
data  compiled  by  the  Rice  Milling  Association. 


42       NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

the  year.  In  Colorado  and  Austin  Counties,  for  example,  approxi- 
mately 80  percent  of  the  best  prairie  chicken  country  was  burned  over 
in  1936.  A  fire  of  accidental  inception  ran  over  about  3,000  acres  of 
the  6,700  acre  J.  C.  Anderson  Estate  ranch,  Harris  County,  in  May 
1937.  The  cover  on  about  3,000  acres  of  the  best  prairie  chicken 
country  in  Matagorda  County  was  intentionally  burned  in  July  1937. 
Pasture  burning  is  an  annual  event  on  the  Pipkin  ranch,  Jefferson 
County,  fires  being  started  during  first  new  moon  after  February  15. 
Areas  that  the  first  fires  do  not  cover  cleanly  are  subsequently  treated, 
and  burning  generally  continues  well  through  the  nesting  season. 
Most  ranchmen,  however,  complete  pasture  burning  by  March. 

The  pastures  are  burned  to  remove  old  grass  and  encourage  tender 
new  growth  more  palatable  to  livestock.  Fires  usually  are  set  when 
the  grass  is  dry  and  the  wind  brisk,  in  order  to  finish  the  job  quickly. 
The  resulting  fast,  hot  fires  entirely  denude  areas  except  in  low  spots 
and  deplete  pastures  of  food,  escape  cover,  and  nesting  sites.  Prairie 
chickens  and  their  natural  enemies  are  crowded  into  unburned  areas 
(pi.  12)  and  predation  is  undoubtedly  intensified.  During  the  breed- 
ing season  fires  destroy  nests  and  probably  many  young  birds  as  well ; 
no  fewer  than  nine  nests  with  charred  eggs  were  found  by  Waddell  in 
a  640-acre  pasture  burned  in  May  1936.  Plant  life  recovers  slowly 
in  the  absence  of  abundant  rain;  consequently,  fires  accentuate  the 
results  of  drought.  Altogether,  fire  is  one  of  the  most  important 
factors  limiting  prairie  chicken  numbers  in  pastures.  When  burning 
is  carried  on  as  outlined  under  Management  (pp.  53  to  54),  however, 
the  evils  are  greatly  reduced  or  entirely  eliminated,  and  benefits 
accrue  to  forage  and  soil  as  well. 

Overgrazing 

With  the  possible  exception  of  Orange  and  Jefferson  Counties,  over- 
grazing is  severe  in  most  of  coastal  Texas  from  late  in  fall  through 
early  spring.  In  addition  to  reducing  cover  and  food  for  prairie 
chickens  (pi.  12),  overgrazing  probably  also  increases  the  vulnera- 
bility of  the  birds  both  to  natural  enemies  and  to  man.  In  Colorado 
County  from  1936  through  1938,  for  example,  it  was  noted  that  marsh 
hawks  and  other  raptors  harried  chickens  more  persistently  in  lightly 
vegetated  pastures  than  in  areas  where  heavy  grassy  cover  was  pres- 
ent. Waddell  observed  that  hunters  regularly  kill  a  higher  percent- 
age of  known  populations  in  areas  where  cover  is  light  than  where  it 
is  heavy.  In  Colorado  County  it  has  been  found  that  the  winter 
prairie  chicken  population  of  a  pasture  can  be  forecast  with  consider- 
able accuracy  by  observing  the  extent  to  which  the  area  is  grazed. 
Large  winter  populations  are  rare  in  pastures  where  cover  is  short. 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


PLATE    12 


B49778;  B60059 

Above,  Excellent  uiihurned  cover  at  right  of  road;  inferior  burned  cover  at  left; 
Colorado  County,  Tex.,  approximately  7  miles  north  of  Eagle  Lake,  December 
22,  1936.  Below,  Scanty  cover  where  there  has  been  overgrazing;  the  shrub  is 
Cherokee  rose  {Ro.sn  laerignla);  Colorado  County,  Tex.,  6  miles  north  of  Eagle 
Lake,  March  7,  1938.      (Photos  by  V.  W.  Lehmann.) 


ATTWATER'S   PRAIRIE    CHICKEN  43 

Aside  from  resulting  unfavorably  to  prairie  chickens,  overgrazing 
in  the  gulf  coastal  country  has  been  and  is  resulting  in  (1)  the  spread 
of  undesirable  brush  and  weeds,  (2)  the  increase  of  needlegrass  and 
other  largely  unpalatable  grasses,  and  (3)  serious  erosion.  An  abun- 
dance of  prairie  chickens  cannot  be  maintained  on  overgrazed  tracts ; 
it  is  equally  impossible  to  maintain  forage  and  soil  on  such  areas. 

Oil  Development 

Oil  development,  which  began  with  the  discovery  of  the  Spindle 
Top  field  in  Jefferson  County  in  1901,  has  extended  to  every  county 
in  the  coastal  section.  All  the  Attwater's  prairie  chicken  area  is 
classed  as  potential  oil  land,  and  almost  every  acre  has  been  surveyed 
not  once,  but  several  times  by  oil  crews.  Veritable  forests  of  oil  der- 
ricks now  stand  in  areas  that  once  provided  some  of  the  finest  prairie 
chicken  range.  In  these  areas,  as  in  Fort  Bend  County,  prairie 
chickens  are  almost,  if  not  completely  gone. 

Dkainagh 

Drainage  canals,  as  in  Brazoria  and  certain  other  coastal  counties, 
have  in  some  instances  improved  the  territory  within  a  mile  or  so  of 
their  margins  by  providing  a  permanent  water  supply  where  it  was 
otherwise  lacking  during  the  summer  months.  On  the  other  hand, 
drainage  canals  have  doubtless  decreased  the  general  wildlife  pro- 
ductivity of  the  counties  in  which  they  are  situated  by  speeding  up 
the  run-off  and  thus  lowering  the  water  table.  Until  recently  many 
prairie  ponds  retained  water  throughout  the  year,  produced  crappie, 
bream,  and  other  edible  fish,  held  safe  nesting  cover  for  black 
mallards  and  other  water  birds,  grew  an  abundant  supply  of  food  for 
wintering  waterfowl,  and  served  as  concentration  points  for  prairie 
chickens  during  the  heat  of  summer.  Now  they  go  dry  during  the 
slightest  drought  and  produce  virtually  nothing. 

PASTtTRE  Mowing 

Regular  mowing  of  grassy  areas,  mainly  for  hay  or  increased 
forage  production,  has  promoted  a  nearly  pure  stand  of  grass  in  some 
of  the  areas  treated  and  has  reduced  shade  and  food,  and  the  general 
attractiveness  of  the  areas  for  prairie  chickens  and  certain  other 
valuable  wildlife.  In  Colorado  County,  areas  that  have  been  mowed 
regularly  for  long  periods  are  virtually  game  deserts;  prairie  chickens 
use  them  little  even  at  nesting  time.  Pasture  mowing  in  coastal 
Texas  appears  to  be  extending  rapidly,  and  further  reduction  in 
wildlife  resources  may  be  expected  from  this  cause  unless  definite 

303807°— 41 4 


44      NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

modifications  are  effected.  Fortunately,  the  detrimental  effects  of 
pasture  mowing  to  upland  game  birds  may  be  mitigated,  at  least  to 
some  extent,  by  following  management  recommendations  listed  on 
page  66. 

Mechanical  Accidents 

Prairie  chickens  sometimes  fly  into  telephone  wires,  fences,  and 
houses,  or  are  struck  by  automobiles.  In  six  instances  in  1937  birds 
were  noted  as  accidentally  killed  in  the  Eagle  Lake  section — as  many 
as  were  recorded  for  predation.  Mortality  from  accidents  may  be 
far  more  serious  than  is  generally  appreciated. 

Hunting 

Last,  but  not  least,  hunters  certainly  have  contributed  to  prairie 
chicken  decrease.  Hunting  has  never  been  well  regulated,  and  laws 
governing  the  taking  of  the  birds  have  always  been  inadequate.  Ac- 
cording to  the  Texas  Game,  Fish,  and  Oyster  Commission  (Ann. 
Kept.,  1929:  86-91)  prairie  chickens  had  no  legal  protection  until 
1883,  when  a  5-month  closed  season  was  declared  during  the  breeding 
period.  In  1885, 148  counties  claimed  partial  or  total  exemption  to  this 
and  other  regulations,  and  it  was  not  until  1903  that  the  legislature 
passed  a  bill  designating  the  months  of  November,  December,  and  Jan- 
uary as  the  open  season  and  setting  a  daily  bag  limit  of  25.  The  legis- 
lation of  1908  was  indeed  a  forward  step,  but  there  was  no  conserva- 
tion body  to  enforce  the  m.easure,  local  officers  being  depended  on 
to  carry  out  its  provisions.  The  Game,  Fish,  and  Oyster  Commis- 
sion was  not  created  mitil  1910,  and  for  many  years  it  was  without 
adequate  funds  and  personnel.  As  late  as  1919  there  were  only 
6  salaried  wardens  in  Texas  endeavoring  to  carry  out,  as  best  they 
might,  almost  wholly  inadequate  regulations.  The  law  restricting 
the  open  season  on  prairie  chickens  to  4  days,  September  1  to  Sep- 
tember 4,  inclusive,  and  the  bag  limit  to  10  a  day  or  10  a  season, 
was  not  passed  until  1929.  In  1937  there  were  only  9  full-time 
wardens  in  all  the  Attwater's  prairie  chicken  country,  and  they  were 
charged  with  patrolling  more  than  8  million  acres ! 

Development  of  the  coastal  territory,  as  farming,  grazing,  and 
the  exploiting  of  oil,  crowded  prairie  chickens  into  ever  smaller 
areas,  where  they  were  more  easily  found  and  killed.  The  Hug- 
the-Coast  Highway  (State  Highway  No.  35)  and  various  other  roads 
increased  patrol  problems;  the  intercoastal  canal  in  Galveston,  Cham- 
bers, and  Jefferson  Counties  made  formerly  remote  areas  easily 
accessible  to  poachers.  The  number  of  hunters  increased  as  trans- 
portation facilities  and  weapons  were  improved.  The  open  season  in 
September,  normally  a  dry  period  (see  pp.  57  to  68),  did  much  to 


ATTWATER'S   PRAIRIE    CHICKEN  45 

popularize  hunting  from  automobiles.  With  these  and  other  advan- 
tages, hmiters  evidently  harvested  too  closely.  In  the  Bernard  River 
country  (western  Austin  County  and  northeastern  Colorado  Coimty), 
for  example,  it  is  known  that  in  1936  hunters  killed  66  chickens,  or 
22  percent  of  the  estimated  total  population  (300).  This  was  accom- 
plished despite  the  fact  that  the  gunners  were  closely  supervised  and 
did  not  hunt  in  the  most  densely  populated  pastures.  It  is  probable 
that  excessive  kills  have  occurred  in  other  areas  for  many  years; 
the  1937  census  showed  that  Attwater's  prairie  chickens  were  nearly 
or  completely  extirpated  except  on  or  adjoining  lands  where  they  had 
been  hunted  little,  if  at  all,  for  at  least  10  years.  In  Harris,  Galves- 
ton, Waller,  and  possibly  in  parts  of  other  counties,  hunting  has 
probably  been  the  agency  most  largely  responsible  for  prairie  chicken 
decline. 

MANAGEMENT 

Leopold  (1931 :  3)  has  defined  game  management  as  the  art  of 
making  land  produce  annual  crops  of  wild  game  for  recreational  use. 
In  coastal  Texas,  the  management  of  prairie  chickens  must  consist 
largely  of  the  preservation  of  suitable  grassland  areas.  Increased 
protection,  habitat  improvement,  adequate  predator  control,  and 
proper  regulation  of  the  harvest,  hovvever,  will  greatly  encourage 
recovery. 

PROTECTION 

An  act  (H.  B.  30)  passed  by  the  State  legislature,  effective  Sep- 
tember 24,  1937,  forbade  the  killing  of  prairie  chickens  in  Texas  for 
a  period  of  5  years.  This  measure  removes  much  of  the  pressure 
previously  exerted  on  the  birds  during  the  regular  open  hunting  sea- 
son, for  true  sportsmen  will  observe  the  decree.  Landowners,  game 
wardens,  and  other  interested  individuals,  however,  will  remember 
that  close  seasons  may  tend  to  stimulate  rather  than  retard  the  opera- 
tions of  game  bootleggers.  According  to  the  consensus  of  State 
game  wardens  in  the  coastal  territory,  violators  are  especially  active 
(1)  during  the  birds'  spring  courtship  season  when  the  conspicuous 
males,  their  instincts  of  self  preservation  dulled  by  the  the  mating 
urge,  are  easy  targets  for  .22-caliber  rifles;  (2)  late  in  July  and 
August,  when  the  tame  young  birds  are  of  "frying"  size;  and  (3) 
during  the  duck  season,  when  whirring  flocks  of  Attwater's  prairie 
chickens  evidently  tempt  gunners  who  have  insufficient  self  control. 
Coastal  game  wardens  report  that,  in  years  past,  probably  as  many 
prairie  chickens  were  illegally  killed  during  the  duck  season  as  were 
taken  legally  during  the  then  open  season  in  September.  The  restora- 
tion of  the  species  demands  close  protection  for  the  remaining  birds 
at  all  times. 


46       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

Although  game  wardens  in  the  prairie  chicken  country  are  sin- 
cere and  energetic,  the  territory  is  too  vast  for  adequate  protection 
under  the  facilities  available.  Sportsmen  may  render  valuable  aid 
by  helping  conservation  officers  apprehend  irresponsible  hunters,  but 
landowners  or  their  resident  agents  must  handle  the  job  if  prairie 
chickens  are  to  receive  anything  like  adequate  protection.  Land- 
owners, individually  or  in  groups,  would  do  well  to  incorporate  their 
holdings  to  form  game-management  areas,  as  advocated  by  the  Ex- 
tension Service,  Texas  Agricultural  and  Mechanical  College  and  the 
Texas,  Game,  Fish,  and  Oyster  Commission.  Under  that  plan,  in- 
creased protection  is  provided  through  appropriate  posting  and 
provision  by  the  landowners  of  qualified,  resident,  free-service  State 
game  wardens.  Also  technical  service  is  given  in  solving  predator 
problems,  improving  wildlife  food  and  cover,  properly  regulating 
harvests,  and  otherwise  maintaining  wildlife  crops.  Nonresident 
owners  should  check  up  on  the  manner  in  which  their  foremen 
or  lessees  protect  wildlife  during  their  absence.  It  is  regrettably 
true  that  some  supposedly  protected  ranches  are  in  reality  hunting 
clubs  for  irresponsible  agents  and  their  friends  when  the  landowners 
are  away.  Long-time  lessees  who  wish  to  manage  prairie  chickens  or 
other  game  should  insist  that  their  contract  include  control  over  the 
wildlife  resources  of  the  property  as  well  as  over  grazing  or  other 
values.  These  lessees  may  thus  avoid  embarrassment  from  unwel- 
come hunter  guests  directed  to  the  area  by  the  absentee  owners. 

Landowners  who  contemplate  leasing  their  holdings  for  oil  develop- 
ment might  well  follow  the  precedent  set  by  a  ranch  owner  in  Refugio 
County.  Each  of  his  contracts  carries  the  provision  that  the  lease 
shall  terminate  immediately  after  any  representative  of  the  contract- 
ing company  is  caught  on  the  property  with  a  gun  of  any  kind. 
Such  a  clause  properly  shifts  the  burden  of  supervising  irresponsible 
oil  workers  from  the  landowner  to  the  oil  company. 

Increased  protection  of  the  few  remaining  Attwater's  prairie 
chickens  is  necessary  for  success  in  management.  Protection  alone, 
however,  is  largely  ineffective  in  areas  where  proper  food  and  cover 
conditions  are  lacking. 

HABITAT  IMPROVEMENT 

At  present  there  are  few  areas  in  Texas  where  excellent  conditions 
for  prairie  chickens  prevail,  and  populations  fluctuate  markedly 
(table  15).  Increase  or  decrease  in  study  areas  was  thought  fre- 
quently to  coincide  with  fluctuations  in  the  supplies  of  food,  cover, 
or  surface  water.  In  many  areas  marked  seasonal  movements  may 
be  averted  and  larger  and  more  stable  populations  maintained  by 
removing  deficiencies  in  habitat. 


ATTWATER'S   PRAIRIE    CHICKEN 


47 


Table  15. — Fluctuations  in  numbers  of  prairie  chickens,  Thomas  and  Koy  pas- 
tures, Colorado  County,  1937 


Size 

Prairie  chickens  found 

Pasture 

Feb. 
221 

Apr. 
13 

May 
2 

June 
2, 8, 10 

July 
26 

Sept. 
1 

Oct. 
22 

Nov. 
1 

Thomas 

Acres 
817 
460 

Num- 
ber 
31 
0 

Num- 
ber 
30 
0 

Num- 
ber 
28 
0 

Num- 
ber 
37    16 
14 

Num- 
ber 
0 
23 

Num- 
ber 
17 
32 

Num- 
ber 
0 
0 

Num- 
ber 
1 

Koy    -  ...  .-           

0 

1  Count  of  birds  at  or  near  the  courtship  grounds;  no  allowance  made  for  any  birds  that  may  have  been 
missed.    All  other  counts  were  by  the  rope  method.    (See  p.  49.) 

Evaluating  Conditions 

In  some  instances  it  is  relatively  easy  to  point  out  one  or  more  ways 
in  which  areas  are  inferior.  Safe  nesting  cover  is  deficient  in  burned 
pastures  that  are  devoid  of  old  vegetation  except  in  low  damp  places. 
Shade  is  insufficient  on  lands  kept  free  of  tall  weeds  or  shrubs  by 
mowing  or  grazing.  Winter  food,  or  cover,  or  both  are  usually  lack- 
ing in  areas  having  few  native  food-cover  plants,  as  ragweed, 
goatweed  (Croton),  marsh-elder,  or  ruellia.  Sometimes,  however, 
habitat  deficiencies  are  obscure  and  general  observations  of  an  infre- 
quent nature  do  not  identify  them.  Accurate  inventories  are  of 
assistance  in  determining  (1)  whether  habitat  improvement  is  needed, 
(2)  what  should  be  done,  (3)  results  of  work  done,  and  (4)  the  sur- 
plus available  for  hunting.  Management  programs  should  be  formu- 
lated on  the  basis  of  data  obtained  during  inventories  conducted 
thrice  annually,  in  spring,  summer,  and  winter.  Inventory  methods, 
recording  and  interpreting  data,  and  management  practices  are  dis- 
cussed in  the  following  paragraphs. 

CBajsus  Methods 


SPBING  COUNT  ON   THE  COURTSHIP  GROUNDS 

The  first  census  method  that  has  been  tried  and  found  useful  is 
the  spring  count  of  birds  on  the  courtship  grounds.  Necessary  are 
an  automobile,  preferably  of  light  build  and  high  clearance,  a  driver 
who  is  well  acquainted  with  the  area,  and  someone  to  act  as  observer, 
note  keeper,  and  gate  opener. 

A  count  is  made  on  each  courtship  ground  in  the  area,  recording 
the  number  and  sex  of  birds  assembled  there  and  the  number  and 
sex  of  birds  seen  between  these  grounds.  The  number  of  hens  is 
recorded  as  a  supplementary  check.  The  number  of  males,  increased 
80  to  110  percent  to  allow  for  females  that  will  be  missed  is  accepted 
as  the  total  population  of  the  census  area.    For  best  results,  the 


48       NORTH  AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

spring  count  is  made  in  March  from  daybreak  to  about  7 :  30  a.  m. 
A  population  estimate  based  on  the  maximum  count  obtained  by 
reworking  the  same  area  three  successive  mornings,  or  often  enough 
to  offset  variations  due  to  unfavorable  weather,  is  likely  to  be  suffi- 
ciently accurate.  Where  recounts  are  impracticable,  the  single  enu- 
meration should  be  made  on  a  clear,  quiet  morning  after  a  brisk 
norther. 

Courtship  grounds  may  be  located  by  sight  or  sound  of  the  birds 
assembled  there,  but  it  is  preferable  to  "drive  out"  the  census  area  in 
belts  150  yards  or  less  wide.  Drumming  grounds  should  not  be  ap- 
proached more  closely  than  is  necessary,  because  flushing  the  birds 
leads  to  inaccurate  counts.  As  birds  frequently  squat,  or  freeze,  at 
the  approach  of  a  car,  it  is  desirable  to  wait  at  each  occupied  booming 
ground  and  refrain  from  counting  until  after  vigorous  courtship  ac- 
tivity has  been  resumed.  It  is  good  policy  to  encircle  a  counted  area 
completely  before  proceeding  to  a  new  site,  for  the  fresh  car  tracks 
often  assist  in  avoiding  duplication. 

The  accuracy  of  spring  counts  on  the  courtship  grounds  was  tested 
in  the  following  ways:  (1)  A  section  (640  acres)  was  covered  on  10 
successive  mornings;  (2)  a  1,000-acre  pasture  was  searched  with  the 
aid  of  15  bird  dogs;  (3)  a  1,000-acre  pasture  was  recounted  by  5  men 
using  2  cars,  3  horses,  and  2  dogs ;  (4)  a  section  worked  3  successive 
days  was  rope  counted.  Spring  counts  have  been  made  over  ap- 
proximately 150,000  acres  in  Colorado,  Wharton,  and  Austin  Counties. 
These  studies  show  that  the  enumeration  of  birds  on  the  courtship 
grounds  is  the  most  rapid  and  economical  of  all  known  census  tech- 
niques. More  than  2,000  acres  a  morning  have  often  been  covered  in 
areas  having  populations  of  about  1  bird  per  45  acres.  There  are  no 
indications  that  the  method  affects  courtship  activities  adversely  or 
that  it  greatly  endangers  early  nesting.  Also,  the  spring  count  of 
males  is  useful  in  yielding  data  on  prairie  chicken  abundance  in  com- 
parable areas  worked  at  nearly  the  same  time  and  under  nearly  the 
same  conditions. 

The  spring  count  of  birds  on  the  courtship  grounds,  however,  is 
not  without  its  defects.  Its  accuracy  is  influenced  by  weather  and 
other  conditions  at  a  time  convenient  for  counting.  Opportunity  is 
limited  to  a  few  hours  a  day  (from  about  6  to  7 :  30  a.  m.)  over  a  short 
period  (in  March).  The  spring  count  does  not  reveal  the  number  of 
females  present,  consequently,  it  does  not  produce  reliable  quantita- 
tive data  on  sex  ratio  and  total  population.  Some  observers  experi- 
ence difficulty  in  distinguishing  males  from  females,  especially  in  the 
poor  light  of  early  morning.  To  them  the  analysis  of  sex  differences, 
presented  on  p.  49,  may  be  helpful. 


North  American  Fauna  57,  Fish  and  Wildlife  Service 


PLATE    13 


V«if 


B49329;   B489:9 


Above,  Rope  counting  uf  prairie  ctncl^ens  on  Matagorda  Island,  Tex.,  October  30, 
1937.  Below,  Rope  counting  in  myrtle  bru.sh;  Liberty  County,  Tex.,  approxi- 
mately 8  miles  southeast  of  Devers,  June  27,  1937.     (Photos  by  W.  P.  Taylor.) 


ATTWATERS    PRAIRIE    CHICKEN 


49 


FIELD    BASIS    FOR    DIFFERENTIATION    OF    THE    SEXES   IN    SPRING 

Basis                                         Males  Females 

General  color Light  gray Brownish  gray. 

Color  of  breast Not    perceptibly    different  Much  lighter  than  that 

from  that  of  back.  of    back;    appears    al- 
most white  in  flight. 

Barring    on    back    and     Heavj^  black,  well  defined.  _  Light,     brownish    black, 

breast.  poorly  defined. 

Color  of  head Orange  -  colored     comblike  Orange -colored    combs 

structure   present   above  absent. 

each  eye. 

Feathers  of  crest Seldom  erect Frequently  erect. 

Neck Appears  thick  and  heavy,  Appears   thin   and   long; 

with  large,  brightly  col-  air  sac  and  neck  tufts 

ored     (orange)     air     sac  rudimentary    {%&  inch 

apparent  on  each  side  of  long). 

neck     under     prominent 

(2.25  to  2.90  inches)  neck 

tufts. 

Size Large,  heavy  (about  2}Ob.)-  Small,    light    (about   1% 

lb.). 

Action      on      courtship     Bold,    struts,    fights,    and  Shy,  does  not  strut,  fight, 

grounds.                                 booms  in  open  cover.  or  boom. 

Flocking Usually  in  groups  of  8  to  12  Usuallj^  alone. 

when    booming,    feeding, 

or  resting  at  midday. 

Flushing Laborious  take-off;  cackles  Easy     take-off;     usually 

when  rising  from  ground.  does  not  cackle. 


THE  BOPE  COUNT 


A  second  method  of  counting,  one  that  has  been  tested  with  most 
encouraging  results  in  the  coastal  prairie  chicken  country,  is  the  rope 
count  (pi.  13).  Essential  equipment  includes  two  automobiles, 
preferably  of  light  build  and  high  clearance,  an  inch  rope  or  a 
quarter-inch  flexible  steel  cable  60  to  120.  yards  in  length,  and  two 
strong  swivels.  An  extra  supply  of  water  for  radiators  is  needed 
in  hot  weather  as  cars  heat  up  under  the  heavy  going.  In  addition 
to  drivers  for  the  two  cars,  a  third  person  should  be  taken  along,  if 
possible,  to  act  as  note  keeper  and  general  handy  man. 

When  the  census  area  is  reached,  one  swivel  is  attached  to  the 
right  end  of  the  rear  bumper  of  the  car  in  which  the  note  keeper 
is  to  ride,  and  the  second  swivel  is  attached  to  the  left  end  of  the 
rear  bumper  of  the  other  machine.  Each  end  of  the  rope  or  cable 
is  then  securely  tied  to  a  swivel.  Care  must  be  exercised  to  see  that 
the  rope  or  cable,  in  turning,  will  tighten  its  twist  and  not  loosen  or 
unravel.  One  machine  takes  position  parallel  to  a  fence  or  other 
definite  landmark  while  the  other  goes  far  enough  way  to  stretch  the 
rope  so  that  only  a  slight  bend  remains.  After  both  cars  are  in 
position,  they  drive  over  parallel  courses  at  a  uniform  speed  of  5 


50      NORTH  AMERICAN   FAUNA    57,   FISH  AND   WILDLIFE    SERVICE 

to  15  miles  an  hour,  which  may  be  increased  in  light  cover  but 
which  should  be  reduced  in  heavy  vegetation  to  keep  the  rope,  for 
the  greater  part  of  its  length,  about  5  inches  above  ground.  Birds 
are  tabulated  as  they  are  flushed.  Those  flying  into  uncovered  ter- 
ritory are  deducted  when  that  area  is  dragged.  When  the  end  of 
a  strip  is  reached,  the  car  in  which  the  note  keeper  rides  turns  and 


J^ 


Belts.  En<iHftr«-», 


Icftal 


I 


6elt4. 


Beit  3. 


Belil. 


(eSI 


ftope-»«  5tart  Here »  2*="  '• 

s 


FiGtTEE  4. — ^Diagram  of  the  rope  count.    Arrows  show  course  of  each  car. 

retraces  its  course  while  the  other  car  makes  a  wide  swing  to  the 
outside  margin  of  another  belt  (fig.  4).  This  is  repeated  until  every 
part  of  the  census  area  has  been  covered. 

The  principle  of  rope  counting  is  not  new.  Askins  (1931:  8)  re- 
ports that  market  hunters  and  others  in  Kansas  "*  *  *  hitched 
a  wire  between  two  wagons  and  with  these  driving  across  the  prairie 
300  yards  apart,  the  gunners  walked  behind  the  wire  taking  the 
grouse  as  they  arose  until  the  wagon  was  filled."    Butchers  of  wild- 


ATTWATER'S   PRAIRIE    CHICKEN  51 

life  (they  have  no  claim  to  the  title  of  sportsmen)  have  used  modi- 
fications of  this  system  in  coastal  Texas  for  years. 

The  rope  census  method  has  been  checked  and  rechecked  for  ac- 
curacy against  the  spring  counts  of  birds  on  the  drumming  grounds, 
car  counts,  and  counts  with  bird  dogs.  The  rope  count,  by  far  the 
most  efficient  of  all,  has  been  tried  over  approximately  45,000  acres 
of  grouse  range,  including  every  major  prairie  type  in  which  Att- 
water's  prairie  chickens  occur  in  Texas.  Heavy  myrtle  brush,  as 
in  Jefferson,  Liberty,  and  other  counties  east  of  the  Brazos  River, 
light  to  heavy  Pasyahmv-Andro'pogon  grassland  as  in  Brazoria  and 
Colorado  Counties,  live  oak  shinnery  in  the  northern  part  of  Vic- 
toria County,  rough  weedy  hog  wallow  blackland  of  Eefugio  County, 
and  even  the  extremely  rough  salt-grass  area  of  the  same  section, 
have  all  been  negotiated  successfully.  These  tests  have  demonstrated 
clearly  the  practicability  of  the  rope  coimt  under  all  coastal  prairie 
conditions.  Another  advantage  is  speed;  a  party  can  easily  cover 
2,000  acres  a  day ;  Waddell  and  the  writer  having  counted  the  birds 
on  an  area  of  this  size  in  one  morning. 

Ropes  last  for  a  considerable  period,  one  that  has  been  dragged 
over  20,000  acres  still  being  used.  This  method  of  counting  is  not 
closely  limited  to  a  short  season,  or  to  a  particular  part  of  the  day, 
as  is  the  spring  count  on  the  courtship  grounds.  The  accuracy  of 
the  rope  count  is  not  dependent  on  special  weather  conditions  or  on 
other  variables  over  which  man  has  no  control,  its  major  advantage 
lying  in  the  fact  that,  when  properly  used,  it  gives  an  accurate 
quantitative  count  in  the  census  area.  For  that  reason,  it  is  most 
useful  in  prairie  chicken  management. 

The  rope  count  is  dangerous  for  the  layman  to  use  during  the 
nesting  season  and  when  young  birds  a.re  small  (during  the  latter 
part  of  March  through  June),  for  unless  extreme  care  is  taken,  nests 
may  be  broken  up  and  young  birds  injured,  scattered,  or  even  killed 
by  a  fast-moving,  1-inch  rope.  A  i/4-inch  rope,  50  yards  long,  how- 
ever, has  been  used  with  success  in  locating  nests  and  broods  without 
detriment  to  the  birds.  Coffee-bean  plants,  yaupon  bushes,  trees, 
and  old  fence  posts  are  obstacles  to  rope  counting,  but  they  can  be 
avoided  without  great  loss  of  time,  and,  with  care,  few  breaks  in 
the  rope  or  cable  result.  Of  course,  cultivated  fields  cannot  be 
traversed  without  injury  to  standing  crops,  and  counting  is  difficult 
and  sometimes  impossible  in  fallow  rice  fields  where  levees  are  high. 
Inexperienced  persons  sometimes  have  trouble  in  keeping  the  proper 
amount  of  slack  in  the  rope  and  in  following  the  car  tracks  which 
are  depended  upon  to  mark  the  inside  margin  of  every  new  belt. 
These  minor  difficulties,  however,  are  rapidly  overcome  by  practice. 


52       NORTE   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

CAH-DOG    COUNT 

A  car-dog  count  is  made  by  driving  out  an  area  in  belts  40  to 
150  yards  wide  and  releasing  dogs  to  work  the  area  where  birds  are 
known  or  strongly  suspected  to  be.  Necessary  equipment  consists  of 
one  car  and  one  well-trained  dog,  but  two  cars,  with  a  man  and  two 
dogs  in  each,  speed  up  the  work  more  than  100  percent. 

Since  1936  this  method  has  been  employed  in  working  over  25,000 
acres.  It  is  economical  and  is  highly  enjoyable  to  dog  lovers,  but 
it  is  slow.  The  work  of  different  dogs  and  that  of  the  same  dog  at 
different  times  and  under  different  conditions  varies  greatly.  Dup- 
lications in  counts  or  recounts  are  virtually  unavoidable  on  well- 
populated  range,  and  misses  are  frequent.  As  reliable  data  are  diffi- 
cult to  obtain  by  this  method,  it  should  be  used  only  when  other  census 
techniques  are  impossible. 

Using  the  Census 

Censuses  produce  the  most  dependable  information  when  applied 
over  an  entire  management  area.  Wliere  this  is  impracticable  and 
sampling  is  resorted  to,  care  must  be  taken  to  insure  that  the  selected 
area  is  typical  with  respect  to  vegetation,  topography,  water,  and  the 
like,  and  is  sufficiently  large.  In  a  pasture  consisting  of  60  percent 
flat  grassland  with  little  or  no  brush  and  40  percent  sandhills  covered 
with  live  oak  shinnery  it  would  be  incorrect  to  sample  only  the  sand- 
hill territory  and  apply  the  findings  to  the  flat  grassland  as  well. 
Sampling  should  be  divided  proportionately  between  distinct  environ- 
mental types.  Sample  areas  should  be  at  least  a  section,  or  640  acres, 
in  size,  and  they  should  preferably  cover  2,000  acres.  Thoroughness 
should  never  be  sacrificed  for  extent  of  coverage,  however,  as  accurate 
censuses  made  thrice  annually  on  a  well-chosen  section  over  a  period 
of  several  years  will  yield  infinitely  more  usable  data  than  will  hap- 
hazard counts  sporadically  undertaken  over  more  territory  than  can 
be  conveniently  handled. 

During  the  spring  census,  investigators  should  list  (1)  males,  (2) 
females,  (3)  occupied  courtship  grounds  and  the  number  of  males  at 
each,  (4)  unoccupied  courtship  grounds,  and  (5)  jack  rabbits,  in  areas 
where  they  are  a  common  resident  species,  as  in  the  country  west  of  the 
Brazos  River.  Census  sheets  should  show  also  (1)  name  of  the  pasture, 
(2)  name  of  owner,  (3)  size  of  sample  area,  (4)  exact  location,  (5) 
date  of  census,  (6)  counting  method  used,  (7)  weather,  and  (8)  names 
of  the  investigators.  Additional  notes  taken  should  describe  (1)  the 
type  of  country  censused,  whether  flat  grassland  with  few  weeds, 
rolling  country  with  scattered  myrtle  bushes,  and  so  on ;  (2)  grazing 
pressure,  whether  light,  medium,  or  heavy;  and  (3)  recent  burns  on 
high  or  low  ground,  showing  the  percentage  of  area  burned,  whether 


ATTWATER'S   PRAIRIE    CHICKEN  53 

burn  is  general  or  spotty,  and  the  location  of  unburned  cover.     Care- 
ful compilation  of  data  greatly  facilities  accurate  interpretation. 

If  prairie  chickens  are  numerous  in  the  sample  area,  1  to  every 
10  acres  or  less,  cover  conditions  should  not  be  changed.  Instead, 
steps  should  be  taken  to  insure  that  grazing  and  burning  practices 
will  duplicate  the  conditions  in  future  years.  If  the  birds  are  scarce, 
less  than  1  to  every  10  acres,  and  if  they  have  not  been  overshot,  habitat 
deficiencies  should  be  sought  and  corrected. 

SPRING 

Probable  habitat  deficiencies  limiting  prairie  chicken  numbers  in 
spring  are  scanty,  poorly  distributed,  or  overdense  nesting  cover 
and  a  shortage  of  suitable  courtship  grounds.  Common  causes 
of  deficient  cover  are  general  burnmg  and  overgrazing  that  result  in 
scarcity  or  complete  absence  over  more  than  60  percent  of  the  area 
of  old  vegetation,  left  from  previous  years  at  an  average  height  of 
at  least  5  inches,  and  poorly  distributed  cover  confined  to  a  particular 
part  of  a  pasture  or  to  low,  poorly  drained  situations.  Undergrazing 
is  the  usual  cause  of  overdense  cover,  the  thick  matted  vegetation  that 
chickens  regularly  avoid.  Where  jack  rabbits  (Taylor,  Vorhies,  and 
Lister,  1935)  are  a  common  resident  species,  they  are  usually  either 
very  numerous,  1  to  every  10  acres  or  less,  or  entirely  absent  where 
cover  is  too  scanty  or  too  poorly  distributed  to  be  suitable  for  nesting 
prairie  chickens.  Jack  rabbits  are  frequently  scarce,  1  to  every  80 
acres  or  more,  however,  in  cover  that  is  overdense.  A  markedly  un- 
balanced sex  ratio,  with  more  than  twice  as  many  male  prairie 
chickens  as  hens,  also  has  been  noted  in  pastures  where  nesting  cover 
was  deficient. 

In  areas  in  which  the  cover  is  scarce  because  of  general  burning, 
conditions  are  improved  by  leaving  40  percent  or  more  of  the  grassy 
cover  unburned  each  year.  Unburned  cover  should  be  well  distributed 
over  the  pasture,  the  gi'eater  part  being  on  the  highest,  best-drained 
ground,  in  j^atches  of  5  to  40  acres.  Favorable  conditions  are  en- 
couraged if  burning  is  carried  on  when  there  is  little  or  no  wind  and 
the  vegetation  is  slightly  damp.  A  quiet  day  following  a  light  shower, 
or  a  still  night  after  the  dew  has  begun  to  fall,  is  preferable.  A  test 
fire  should  be  set  in  a  protected  corner  of  the  pasture.  If  it  burns 
slowly,  consuming  only  the  most  combustible  material,  and  dies  down 
in  5  to  15  minutes,  a  series  of  fires  then  may  be  set  throughout  the 
pasture.  The  number  should  be  strictly  regulated  by  the  acreage  to 
be  burned  and  the  manpower  available  to  curb  the  fires  in  case  of  such 
unforeseen  difficulties  as  a  fresh  breeze  that  may  put  fires  out  of  con- 
trol. The  best  insurance  against  trouble  from  that  cause  is  a  plowed 
fire  lane,  5  to  10  feet  wide,  completely  encircling  the  pasture  and 


54      NORTH   AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

dividing  it  into  blocks  of  approximately  100  acres  each.  All  pasture 
burning  should  be  completed  by  December  or  early  in  January,  well 
in  advance  of  the  nesting  season. 

Moderation  in  grazing  is  important.  Cattle  should  not  be  left  to 
graze  on  a  tract  until  unpalatable  bunch  grasses,  as  smut  grass,  salt 
grass,  big  bluestem,  and  tlie  like,  are  all  that  remain.  Ideal  condi- 
tions are  approached  when  the  number  of  animal  units  is  strictly  regu- 
lated according  to  the  quantity  and  quality  of  the  available  forage. 
This  practice  avoids  a  condition  of  cover  that  is  scanty  in  dry  years 
and  overdense  in  wet  years,  and,  besides  being  favorable  to  prairie 
chickens,  it  conserves  the  soil  and  the  range. 

A  shortage  of  courtship  grounds,  short-grass  areas  from  one-half  to 
10  acres  in  extent  surrounded  by  light  to  medium-heavy  grassy  cover,  is 
frequently  indicated  by  an  unbalanced  sex  ratio  with  more  than  twice 
as  many  females  as  males  or  by  a  preponderant  male  population  of  8 
to  15  or  more  birds  on  each  booming  ground.  Common  causes  of  in- 
adequate courtship  facilities  are  (1)  a  lack  of  hardpan  flats;  (2) 
general  burning,  which  denudes  vegetation  over  a  wide  area  and  causes 
prairie  chickens  to  leave ;  and  (3)  undergrazing,  resulting  in  tall  cover 
even  on  hardpan  areas.  These  deficiencies,  however,  are  remedied  by 
spot  burning  and  moderate  grazing. 

StTMMEB 

Probable  deficiencies  that  limit  the  number  of  birds  in  summer  are 
an  insufficient  supply  of  water  in  dry  years  and  inadequate  shade.  A 
count  made  from  July  1  through  August  10,  preferably  over  the  same 
area  covered  in  spring,  reveals  the  number  of  yomig  produced,  and 
thus  serves  as  a  check  on  the  success  or  failure  of  the  breeding  season. 

The  data  recorded  for  the  summer  count  should  be  the  same  as  for 
the  spring  count  and,  also,  investigators  should  note  (1)  the  number 
of  young,  (2)  the  number,  character,  and  location  of  water  supplies, 
and  (3)  distribution  of  birds  with  i-espect  to  water  and  weedy  cover. 

A  larger  population  of  adult  prairie  chickens  than  was  found  in 
spring  shows  either  that  the  spring  census  was  inaccurate,  or  that 
other  birds  have  moved  in.  In  the  latter  event  no  habitat  manipula- 
tion should  be  attempted  unless  the  resident  population  plus  the  in- 
flux averages  less  than  1  bird  for  every  10  acres,  and  a  larger  popula- 
tion is  desired.  If  the  adult  population  has  decreased  since  spring, 
however,  and  it  is  established  that  poaching  has  not  occurred,  the 
census  data  should  be  examined  for  information  suggesting  causes 
of  the  decline. 

Indications  of  deficient  water  are  the  absence  of  watering  places  a 
mile  or  less  apart,  and  the  concentration  of  birds  and  jack  rabbits  in 
parts  of  the  area  where  water  is  available.    Indications  of  deficient 


ATTWATER'S   PRAIRIE    CHICKEN  55 

shade  are  the  scarcity  of  prairie  chickens  and  jack  rabbits  where  sur- 
face water  obtains.  Ordinary  causes  of  insufficient  water  are  drainage 
and  unusually  dry  seasons.  Water  supplies  can  be  improved  by  clean- 
ing and  deepening  natural  ponds  or  constructing  new  ones,  and  allow- 
ing windmill  pumps  to  spill  over  and  maintain  puddles  nearby. 

Common  causes  of  inferior  shade  are  heavy  grazing  and  mowing. 
Shade  deficiencies  usually  can  be  corrected  naturally  by  moderate 
grazing  and  leaving  unmowed  plots  1  to  10  acres  in  extent  in  flats 
near  ponds.  Other  methods  of  obtaining  and  maintaining  tall  shading 
cover  are  by  (1)  fencing  tracts  from  i^  to  10  acres  in  size  within  100 
yards  of  water  holes  and  leaving  the  fenced  areas  ungrazed ;  (2)  plant- 
ing tamarisk,  chinaberry,  black  locust,  elm,  sycamore,  cottonwood,  or 
other  adapted  trees  near  water  supplies;  (3)  constructing  two  or  more 
brush  racks  5  by  6  by  2  feet  high  on  knolls  on  high  ground  near 
ponds ;  and  (4)  strip  plowing  near  ponds  as  outlined  on  page  56. 

An  increase  of  100  percent  in  the  number  of  prairie  chickens  in  any 
year  is  excellent.  An  increase  of  50  percent  or  less  may  indicate 
either  a  poor  breeding  season  or  abnormally  high  predation.  Eainf  all 
records  for  May  show  whether  breeding  conditions  are  poor;  in  the 
event  heavy  rainfall  is  not  the  causative  agent,  predators  may  be 
responsible.  In  the  latter  instance,  the  niunber  of  predatory  dogs 
and  house  cats  should  be  reduced  by  shooting  or  trapping.  If  a  thor- 
ough job  is  done  and  yet  the  increase  is  small,  the  aid  of  State  or 
Federal  wildlife  technicians  should  be  solicited. 

WINTEE 

In  winter,  a  grouse  habitat  may  be  deficient  in  food,  cover,  or  both. 
This  may  best  be  determined  by  study  of  information  obtained  during 
a  December  or  early  January  reconnaissance  of  territory  that  was 
covered  in  summer.  Except  for  the  data  on  the  number  of  young 
birds  and  on  the  water  supply,  information,  recorded  in  winter  should 
be  the  same  as  that  in  summer,  and  it  should  show  whether  birds  are 
generally  distributed  or  heavily  concentrated  in  small  areas.  The  rope 
count  is  the  preferred  method  of  winter  census,  dog  counts  being  made 
only  when  rope  counting  is  impracticable. 

Assuming  that  poaching  is  not  a  factor,  a  winter  population  larger 
than  that  of  the  summer,  shows  habitat  conditions  on  a  census  area 
already  more  favorable  than  those  in  pastures  nearby  and  suggests  that 
management  be  directed  at  maintenance,  rather  than  at  alteration  of 
environment.  A  winter  population  smaller  than  that  of  the  summer 
suggests  food  or  cover  deficiencies.  Other  indicators  of  such  inad- 
equacies, generally  occurring  together  in  heavily  grazed  areas,  are  a 
prevalence  of  largely  unpalatable  plants,  as  goatweed,  marsh-elder, 
dogfennel,  perennial  ragweed,  smutgrass  {SporohohiS  poiretii),  and 


56       NORTH   AMERICAN   FAUNA    5  7,    FISH   AND   WILDLIFE    SERVICE 

cordgrass;  a  concentration  of  prairie  chickens  in  small  parts  of  the 
area;  and  an  abundance  of  jack  rabbits  (averaging  1  to  every  10  acres 
or  less)  5  or  their  complete  absence.  Indications  that  food  only  is  lack- 
ing are  a  uniform  growth  of  heavily  matted  grass,  a  sparse  growth 
of  weeds,  and  a  scarcity  of  jack  rabbits  (averaging  1  to  every  80  acres 
or  more).  Moderate  grazing  encourages  favorable  food  and  cover 
conditions. 

To  make  up  for  local  shortcomings,  prairie  chicken  managers  may 
establish  (1)  stockproof -fenced  areas  of  i/^  to  10  acres  in  as  large  num- 
bers as  practicable;  (2)  plowed  strips  20  to  50  feet  wide  dividing 
sparsely  inhabited  parts  of  pastures  into  blocks  of  50  to  200  acres ;  and 
(3)  unmowed  patches  of  cover  of  2  to  10  acres  or  more,  situated  not 
more  than  300  yards  apart.  Fenced  areas  should  not  be  grazed,  and, 
if  possible,  half  of  each  fenced  area  should  be  planted  annually  to 
Schrock,  German  millet,  dwarf  milo,  hegari  (pi.  14) ,  or  red-top  cane. 
Brush  racks  built  in  the  corners  of  fenced  areas  attract  quails  as  well 
as  prairie  chickens.  In  average  years  strip  plowing  may  be  done 
with  satisfactory  results  from  December  through  April,  but  February 
is  considered  most  favorable.  The  best  effects  on  experimental  areas 
in  Wliarton  County  and  at  College  Station  have  been  obtained  on 
strips  that  were  plowed  shortly  before  or  after  a  rain  and  harrowed 
immediately  after  the  preliminary  breaking.  Unmowed  patches  of 
cover  should  be  left  on  knolls  or  ridges,  in  flats  around  ponds,  or  in 
other  places  where  sizable  stands  of  weeds  occur. 

General  Recommenditions  for  Habitat  Conteoi. 

Landowners  who  do  not  undertake  intensive  management  of  prairie 
chickens  based  on  counts  made  three  times  a  year  may  adopt  any 
or  all  of  the  following  general  recommendations  with  the  assurance 
that  some  improvement  will  result: 

Pastures  should  be  grazed  moderately  by  livestock. 

Pasture  burning  should  be  completed  before  February  1;  in  excess  of  40 
percent  of  the  pasture  should  be  left  unburned,  with  the  remaining 
cover  well  distributed  in  patches  of  5  to  40  acres  on  the  best  drained 
areas. 

Mowing  should  not  be  done  before  July  1 ;  unmowed  patches  of  2  to  5 
acres  or  more,  not  more  than  300  yards  apart  should  be  left  on  flats, 
knolls,  or  in  other  places  where  there  is  a  good  stand  of  weeds. 

In  summer  windmill  pumps  should  be  allowed  to  form  puddles. 

Px-edatory  house  cats  and  dogs  should  be  rigidly  controlled. 

The  present  5-year  close  season  (efCeetive  September  1937)  should  be 
enforced.  If  and  when  the  season  is  reopened,  not  more  than  35  percent 
of  the  known  population  should  be  shot  when  rainfall  in  May  is  normal 
or  less.  In  years  when  rainfall  in  May  is  approximately  twice  normal, 
no  birds  should  be  killed. 


North  American  Fauna  57.  Fish  and  Wildlife  Service 


PLATE    14 


ATTWATER'S   PRAIRIE    CHICKEN  57 

PREDATOR  CONTROL 

Exhaustive  studies  by  McAtee  (1931, 1932, 1935,  1936),  McAtee  and 
Stoddard  (1930),  Fisher  (1893)),  May  (1935),  and  others  have  dem- 
onstrated rather  conclusively  that  the  food  of  most  flesh-eating  birds 
and  mammals  is  determined  mainly  by  the  availability  of  prey. 
Errington  (1935)  adds  that  predation  is  largely  confined  to  in- 
secure or  surplus  populations;  in  areas  where  there  is  adequate 
food  and  cover,  hawks,  owls,  skunks,  opossums,  and  the  like  feed 
principally  on  the  more  common  rats,  mice,  snakes,  frogs,  and  insects, 
rather  than  on  the  less  numerous,  swift,  and  elusive  game  birds. 
Flesh  eaters  often  are  neutral,  and  may  be  actually  beneficial,  in 
relation  to  sport  and  agriculture.  Specific  data  presented  on  the 
relationships  of  Attwater's  prairie  chicken  and  its  natural  enemies 
(pp.  37  to  40)  are  by  no  means  so  comprehensive  as  desired.  The 
information  at  hand,  however,  apparently  justifies  the  following 
general  recommendations  concerning  predator  control  on  prairie 
chicken  range: 

Feral  house  cats  and  predatory  dogs  may  well  be  controlled. 

Hawks,  owls,  and  fur  animals  should  not  be  killed  indiscriminately,  their 
control  being  limited  to  known  offenders.  Inhumane  pole  traps  should 
not  be  used.  (All  raptorial  birds  except  Cooper's,  sharp-shinned,  and  duck 
hawks,  goshawks,  and  great  horned  owls  are  protected  in  Texas.) 

Fur  animals  should  be  taken  only  during  open  seasons  when  furs  are  prime, 
and  the  harvest  should  be  regulated  to  promote  sustained  yields. 

HARVESTING  THE  SURPLUS 

Former  laws  governing  the  shooting  of  Attwater's  prairie  chickens 
left  much  to  be  desired.  Regulations  in  efiect  from  1925  through 
1937,  providing  an  open  season  from  September  1  through  September 
4  and  a  bag  limit  of  10  birds  a  day  or  10  a  season,  actually  stimulated 
butchery  and  injured  sport.  Hunting  was  allowed  when  birds  were 
easily  found,  many  being  concentrated  near  patches  of  heavy  cover 
near  surface  water.  Unwary  j^oung  of  the  year  were  easily  shot  be- 
cause they  flushed  near  the  gunner,  flew  straight  and  slowly  for  short 
distances,  and  ran  but  little  after  alighting.  Adults  performed  sim- 
ilarly, probably  because  the  weather  was  warm,  the  cover  dense,  and 
because  they  were  in  molt.  September  heat  prohibited  efficient  work 
by  bird  dogs,  so  crippling  losses  were  doubtless  high.  As  it  was 
also  uncomfortably  warm  for  men  to  walk,  hunting  by  cars,  and 
shooting  from  them,  in  violation  of  State  law,  became  the  rule  in 
Colorado  and  Austin  Counties  and  probably  elsewhere  in  coastal 
Texas. 

In  the  future,  the  power  of  making  regulations  might  well  be 
delegated,  under  proper  safeguards,  to  the  State  Game,  Fish,  and 
Oyster  Commission,  which  has  the  benefit  of  information  and  counsel 


58      NORTH   AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

from  its  own  trained  game  protectors  and  from  experienced  sports- 
men, as  well  as  from  wildlife  specialists  connected  with  the  State  and 
Federal  Governments.  This  power  should  allow  for  prompt  modi- 
fication of  regulations  in  response  to  emergencies  of  climate,  or  other 
conditions  affecting  the  welfare  of  the  birds.  The  proper  open  sea- 
son on  Attwater's  prairie  chickens,  assuming  that  the  nmnbers  of 
the  birds  can  be  built  up  to  withstand  the  drain  of  shooting,  cannot 
always  be  determined  in  advance,  and  regulations  should  be  formu- 
lated in  accordance  with  local  conditions  as  they  develop.  The  State 
legislature,  meeting  only  at  2-year  intervals,  must  rely  on  the  State 
Game  Commission  for  appropriate  regulation  of  the  take  of  game; 
and  only  under  that  arrangement  can  the  people  properly  hold  the 
Commission  fully  responsible  for  game  protection. 

If  hunting  is  again  allowed,  geasons  should  not  in  any  case  open 
prior  to  November  15.  Weather  late  in  November  ijs  usually  suffi- 
ciently cool  for  the  comfort  of  men  and  dogs,  and,  normally,  the 
prairies  are  too  wet  to  allow  hunting  from  cars.  The  prairie  chickens, 
already  congregating  in  winter  packs,  are  widely  distributed  and 
strong  flying;  consequently,  they  are  hard  to  find  and  even  more 
difficult  to  hit.  Probably  because  the  young  of  the  year  are  strong 
and  more  worldly  wise,  and  because  the  weather  is  cool  and  the 
ground  cover  reduced,  late  fall  birds  regularly  flush  widely,  twist 
crazily,  fly  swiftly  and  far,  usually  for  a  mile  or  more,  and  run  after 
alighting.  In  other  words  the  Attwater'g  prairie  chicken  in  Novem- 
ber is  a  game  bird  of  the  highest  order;  hunting  it  thoroughly  tests 
the  most  skillful  hunter  and  the  best  bird  dog.  That  is  as  it  should 
be  in  true  sport. 

RESTOCKING 

At  present  the  possibility  that  prairie  chickens  may  be  restored 
by  artificial  planting  is  remote,  as  wild  birds  are  not  available 
for  trapping  and  moving,  and  artificial  propagation  has  shown  little 
promise.  Furthermore,  there  is  no  assurance  that  priarie  chickens, 
if  available,  would  survive  if  moved.  In  Texas  and  Oklahoma,  at- 
tempts to  transplant  lesser  prairie  chickens  have  been  unsuccessful. 
Bent  (1932:  263)  records  the  failure  of  numerous  attempts  to  trans- 
plant the  greater  prairie  chicken  in  northern  States.  A  number  of 
these  birds  introduced  in  the  vicinity  of  the  Sault  Sainte  Marie  and 
McMillan  in  northern  Michigan  persisted  for  a  few  years,  but  F.  F. 
Tubbs,  Michigan  Department  of  Conservation,  writes  that  they  have 
disappeared.  It  is  true  that  no  intensive  efforts  have  been  made  to 
transplant  Attwater's  prairie  chickens  in  southern  Texas,  but  there 
is  no  reason  to  believe  that  they  would  survive  the  process  better 
than  have  their  relatives. 


ATTWATER'S   PRAIRIE    CHICKEN  59 

Natural  restocking,  however,  takeg  place  rapidly  and  efficiently 
when  prairie  chickens  are  properly  protected  and  allowed  to  increase. 
Since  1935  practically  all  suitable  territory  in  Refugio  County  has 
been  restocked  by  natural  spread  from  the  Salt  Creek  Ranch  and 
the  properties  of  Martin  O'Conner.  When  the  birds  are  permitted  to 
increase  elsewhere,  similar  results  may  be  expected. 

SUMMARY 

Attwater's  prairie  chicken,  a  characteristic  bird  of  the  coastal 
prairie,  is  one  of  three  kinds  that  once  occurred  in  Texas.  A  few 
lesser  prairie  chickens,  smaller  and  paler  in  color  than  Attwater's 
subspecies,  still  persist  in  parts  of  the  Texas  Panhandle.  The  greater 
prairie  chicken,  however,  has  been  entirely  extirpated  from  its  former 
habitat  in  the  central  and  northern  parts  of  the  State. 

An  intensive  census  made  in  the  summer  of  1937  revealed  that 
only  about  8,000  to  9,000  Attwater's  prairie  chickens  then  remained 
in  Texas,  approximately  half  of  them  being  in  Refugio  County. 
The  birds  now  inhabit  only  about  450,000  acres,  compared  with  the 
more  than  6,000,000  formerly  occupied.  The  numbers  of  the  coastal 
prairie  chicken  have  declined  99  percent,  and  its  range  has  decreasd 
more  than  93  percent  during  the  past  century. 

The  mating  season  begins  late  in  January  or  early  in  February, 
when  the  males  assemble  on  short-gi-ass  areas  early  in  the  morning 
and  late  in  the  afternoon  and  boom  and  otherwise  display  the  mating 
urge.  Females  are  attracted  to  the  courtship  areas  by  this  activity, 
and  mating  usually  takes  place  there.  Prairie  chickens  are  pro- 
miscuous.   The  booming  is  at  a  climax  in  March  and  ends  late  in  May. 

Nests  containing  eggs  have  been  found  from  February  25  through 
June  17.  The  peak  of  the  laying  period,  however,  is  late  in  March 
and  in  April.  Females  build  their  nests  in  dry  vegetation  of  the 
previous  year  preferred  nesting  sites  being  in  good  cover  in  well-drained 
areas  and  within  5  yards  of  an  opening. 

The  normal  rate  of  laying  is  1  egg  a  day  until  the  average  clutch 
of  12  is  completed,  but  intervals  of  1,  2,  and  even  3  days  are  not 
infrequent.  Subsequent  attempts  to  nest  may  be  made  if  earlier 
nestings  are  terminated  while  booming  is  still  in  progress.  Second 
and  third  nests  apparently  are  made  in  close  proximity  to  those  previ- 
ously destroyed,  which  probably  jeopardizes  their  chances  for  suc- 
cessful termination.  The  mcubation  period  is  23  to  24  days  and 
hatching  occupies  about  2  days  more.  The  peak  of  the  hatching  sea- 
son is  in  May.  Fertility  of  the  eggs  evidently  is  high.  Nest  losses 
in  1937,  however,  were  70  percent  of  13  nests  studied,  and  those  in 
1938  amounted  to  67  percent  of  6  nests. 

303807° — 41 5 


60      NORTH   AMERICAN   FAUNA    5  7,   FISH   AND   WILDLIFE    SERVICE 

In  1937,  of  broods  on  which  accurate  counts  were  obtained,  48 
averaged  5.48  birds  each.  Mortality  of  young  prairie  chickens  is 
highest  (about  50  percent)  in  the  first  4  weeks  after  hatching  and 
comparatively  low  (about  12  percent)  thereafter,  a  large  share  of  the 
early  mortality  being  in  lost  chicks.  Other  known  causes  of  juvenile 
mortality  include  heavy  or  persistent  rains  during  the  brooding, 
drowning  in  rice  fields,  and  depredations  by  natural  enemies.  Fam- 
ily disintegration,  although  gradual,  begins  when  the  chicks  are  6 
to  8  weeks  old.  It  is  completed  after  cold  northers  late  in  October 
and  in  November  induce  fall  flocking,  or  segregation  of  the  birds 
into  flocks  according  to  sex. 

Unstable  and  temporary  groups  of  5  to  15  birds  are  common  from 
September  through  early  October,  but  singles,  pairs,  and  trios  pre- 
dominate at  that  season.  As  fall  passes  into  winter,  flocks  become 
larger,  and  in  December  and  January  groups  containing  35  to  800 
individuals  have  been  observed.  Singles,  pairs,  and  trios,  however, 
may  be  found  throughout  the  year. 

Young  prairie  chickens  evidently  spend  their  first  3  weeks  within 
half  a  mile  of  the  spot  where  hatched.  Late  in  May  and  in  June, 
both  young  and  adults  move  to  territory  where  cover  providing  good 
shade  is  found  within  half  a  mile  of  surface  water,  there  to  remain 
usually  until  September.  When  fall  rains  and  cool  weather  come 
and  the  fall  weeds  mature,  the  birds  scatter  widely,  often  becoming 
common  where  scarce  or  entirely  absent  at  other  seasons.  Concen- 
tration into  areas  where  there  is  moderate-to-heavy  cover  and  ade- 
quate food  is  evident  by  November,  and  populations  in  favorable 
areas  fluctuate  little  from  then  through  spring. 

The  food  of  adult  prairie  chickens  is  about  85  percent  vegetable 
matter  and  15  percent  animal.  With  j'^oung  birds  the  ratio  of  vege- 
table to  animal  is  approximately  reversed.  Favorite  sources  of  plant 
food  are  ruellia,  perennial  ragweed,  blackberry,  doveweed,  and  sensi- 
tive briar.  Leading  animal  foods  are  grasshoppers  and  beetles. 
Greens  (leaves,  flowers,  buds)  are  lowest  in  the  diet  in  November 
and  December;  seeds  are  taken  in  the  smallest  proportions  in  Jan- 
uary, February,  and  March.  Insects  are  least  frequently  captured 
in  November,  December,  and  January. 

Important  factors  limiting  prairie  chicken  abundance  include  ex- 
cessive or  persistent  rainfall  during  the  nesting  season,  heavy  graz- 
ing, excessive  pasture  burning,  agricultural  operations,  and  over- 
shooting. Other  destructive  factors,  not  generally  serious  but  some- 
times locally  disastrous,  include  oil  development,  drainage,  floods, 
drought,  hurricanes,  hail,  the  spread  of  woody  vegetation  into  prairie 
land,  predation,  pasture  mowing,  and  possibly  disease. 


ATTWATERS    PRAIRIE    CHICKEN  61 

Available  records  from  1925  through  1937  show  a  positive  correla- 
tion on  unmanaged  land  between  the  production  of  young  prairie 
chickens  and  rainfall  in  May.  Good  crops  of  young  chickens  are 
brought  off  in  years  when  the  rainfall  in  May  is  1%  inches  or  more 
below  normal.  Fair  broods  are  produced  when  precipitation  in  May 
is  nearly,  or  only  slightly  above,  normal,  while  poor  crops  are  probable 
when  rainfall  in  May  is  about  twice  normal.  If  the  findings  in 
Colorado  County  apply  to  other  parts  of  the  coastal  country,  2  years 
in  5,  on  the  average,  are  favorable  to  prairie  chicken  reproduction, 
2  are  fair,  and  1  is  poor.  Conditions  affecting  reproduction  are  never 
the  same  for  the  entire  range,  for  a  county,  or  even  for  different  parts 
of  the  same  county,  because  of  the  scattered  character  of  local  rains. 
Attwater's  prairie  chicken  is  a  highly  fluctuating  subspecies,  its 
scarcity  or  abundance  depending  to  a  large  extent  on  the  precipita- 
tion in  May. 

The  annual  kill  of  these  birds  cannot  be  intelligently  regulated  by 
such  general  open  seasons  and  general  bag  limits  as  have  applied 
in  Texas  in  the  past,  but  should  be  set,  when  permissible  at  all,  by 
regulation  by  the  State  Conservation  Department  on  the  basis  of  the 
latest  detailed  information  obtainable. 

Optimum  prairie  chicken  range  apparently  consists  of  well-drained 
grassland  supporting  some  weeds  or  shrubs  as  well  as  grasses,  the 
cover  varying  in  density  from  light  to  heavy;  and  with  supplies  of 
surface  water  available  in  summer.  In  short,  diversification  within 
the  grassland  type  is  essential. 

Management  usually  will  involve  protection  against  excessive  kill- 
ing, improvement  of  food  and  cover,  moderate  control  of  predators, 
and  wise  regulation  of  the  harvest.  Responsibility  for  management 
must  be  assumed  by  the  landowner.  Food  and  cover  deficiencies 
can  best  be  recognized  and  their  improvement  and  maintenance  as- 
sured by  careful  counts  of  the  birds  on  part,  or  all,  of  the  managed 
area  at  three  critical  periods  in  March,  July,  and  December. 

To  obtain  and  maintain  favorable  food  and  cover,  the  following 
general  practices  are  recommended:  (1)  Moderate  grazing  of  pas- 
tures; (2)  completing  all  necessary  pasture  burning  before  February 
1  and  leaving  unburned  not  less  than  40  percent  of  the  best  drained 
ground;  (3)  mowing  pastures  after  July  1  and  preserving  the  native 
cover  on  knolls,  around  ponds,  and  m  flats;  (4)  allowing  wind- 
mill tanks  to  spill  over  in  summer  to  increase  the  supply  of  surface 
water;  (5)  controlling  the  numbers  of  feral  house  cats  and  predatory 
dogs;  and  (6)  allowing  the  shooting  of  not  more  than  35  percent 
of  the  known  prairie  chicken  population  in  any  year  when  rainfall 
in  May  is  normal  or  below  and  prohibiting  killing  when  rainfall  in 
May  is  approximately  twice  normal  or  above.  Hunting  seasons 
should  not  open  before  November  15. 


62      NORTH  AMERICAN   FAUNA    57,   FISH   AND   WILDLIFE    SERVICE 

Under  normal  conditions  hawks,  owls,  and  fur  animals  do  not 
appear  to  be  serious  predators  on  Attwater's  prairie  chickens,  and 
should  not  be  killed  indiscriminately. 

Persons  should  not  request  the  Government  to  furnish  prairie 
chickens  for  r^tocking,  because  there  is  no  surplus  for  the  purpose 
and  no  evidence  that  the  birds  can  be  successfully  transplanted. 

In  the  absence  of  ample  reservations  for  the  species  all  other 
favorable  factors  together  cannot  be  counted  on  to  save  the  bird 
from  extinction.  Before  too  late  a  large  tract  or  tracts  of  suitable 
range  should  be  established  as  a  prairie  chicken  refuge  by  the  Federal 
or  State  Government. 

LITERATURE  CITED 

AsKiNs,  Charles  C. 

1931.  Game  bird  shooting.     312  pp.,  illiis.     New  York. 
Bailey,  Florence  Mekriam. 

1927.  Handbook  of  birds  of  the  western  United  States.     Ed.  10,  rev.,  590  pp. 
illus.     Boston  and  New  York. 
Bailey,  Veenon. 

1905.  Biological  survey  of  Texas.     U.  S.  Biol.  Survey  North  Amer.  Fauna 
25.  222  pp.,  iUus. 
Bbnotbe,  Chables  Emil. 

1892.  Life   histories    of   North   American   birds   with    special    reference   to 

their   breeding   habits   and   eggs,    with   twelve   lithographic   plates. 
U.  S.  Nat.  Mus.  Special  Bull.  1,  446  pp. 
1894.  Ti/mpanuchus  americanus  attwateri  Bendire.     Attwater's  or  southern 
prairie  hen.     Auk  11:  130-132. 
Bent,  Abthue  Cleveland, 

1932.  Life  histories  of  North  American  gallinaceous  birds.     V.  S.  Nat.  Mus. 

Bull.  162,  490  pp.,  illus. 
Bbay,  William  L. 

1901.  The   ecological   relations   of  the   vegetation   of  western   Texas.     Bot. 
Gaz.   32:9^123,   195-217,   262-291,  illus. 
Eekington,  Paul  Lesthb. 

1935.  Overpopulation  and  predation :  A  research  field  of  singular  promise. 
Condor  37:  230-232. 
FiSHEB,  Albert  Kenrick. 

1893.  The  hawks  and  owls  of  the  United  States  in  their  relation  to  agri- 

culture.    U.   S.  Dept.  Agr.  Biol.   Survey    (Orn.   and  Mamm.)    Bull. 
3,  210  pp.,  illus. 
Gross,  Alfred  Otto. 

1930a.  The  Wisconsin  prairie  chicken  investigation.     Amer.  Game  19:  39-40, 

50. 
1930b.  Progress  report  of  the  Wisconsin  prairie  chicken  investigation.     Wis- 
consin Conserv.  Comn.  112  pp.,  illus.     Madison,  Wis. 
Leopold,  Aldo. 

1931.  Report  on  a  game  survey  of  the  North  Central  States.     299  pp.,  illus. 
Madison,  Wis. 

1933.  Game  management.     481  pp.,  illus.     New  York  and  London. 
May,  John  Bichabd. 

1935.  The  hawks  of  North   America.     140  pp.,    illus.     Nat.   Audubon    Soc, 
New  York. 


ATTWATERS    PRAIRIE    CHICKEN  63 

McAtee,  Waido  Lee. 

1931.  A  little  essay  on  vermin.    Bird-Lore  33 :  381-384. 

1932.  Confusions  of  an  economic  ornithologist.     Bird-Lore  34 :  315-321. 

1935.  Food  habits  of  common  hawks.     U.  S.  Dept.  Agri.  Circ.  370,  36  pp., 

illus. 

1936.  The  Malthusian  principle  in  nature.     Sci.  Monthly  42 :  444-456. 
and  Stoddard,  Hhbbebt  Lee. 

1930.  American  raptores  and  the  study  of  their  economic  status.     Condor 

32:  15-19. 
Merrill,  James  Gushing. 

1879.  Notes  on   the  ornithology  of  southern  Texas,  being  a   list  of  birds 
observed  in  the  vicinity  of  Fort  Brown,  Texas,  from  February,  1876, 
to  June,  1878.     U.  S.  Nat.  Mus.  Proc.  1:  118-173,  1878. 
Obebholsite,  Haket  Church. 

1938.  The  bird  life  of  Louisiana.     834  pp.,  illus.     New  Orleans. 
Simmons,  George  Finlat. 

1925.  Birds  of  the  Austin  region.     387  pp.,  illus.     Univ.  Texas,  Austin. 
Stbeckee,  John  Kern. 

1927.  Notes  on  the  ornithology  of  McLennan  County,  Texas.    Baylor  Univ. 
Mus.  Spec.  Bull.  1,  65  pp. 
Stoddard,  Herbert  Lee. 

1931.  The  bobwhite  quail:  its  habits,  preservation,  and  increase.     559  pp., 

illus.    New  York. 
Tatlor,  Walter  Penn. 

1934.  Significance  of  extreme  or  intermittent  conditions  in  distribution  of 

species  and  management  of  natural  resources,  with  a  restatement 
of  Liebig's  law  of  minimum.     Ecology  15 :  374-379. 
VoRHiES,  Charles  Taylor;  and  Lister,  Paul  B. 

1935.  The  relation  of  jack  rabbits  to  gi-azing  in  southern  Arizona.     Jour. 

Forestry  33 :  490-498,  illus. 
Texas  Game,  Fish,  and  Oyster  Commission. 

1929.  Grouse  or  prairie  chicken.    Ann.  Rpt.  1929:  86-91,  illus.    Austin,  Tex. 
Tharp,  Benjamin  Carroll. 

1926.  Structure  of  Texas  vegetation  east  of  the  98th  meridian.     Univ.  Texas 

Bull.  2606,  100  pp.,  illus.     Austin,  Tex. 


INDEX 


Abundance,  6,    7. 
Agricultural  factors,  40. 
americanus,  Tympanuchus,  4. 
attwateri,  Tympanuchus  cupido,  1. 

Brood  size,  18. 

Call,  12. 

Cat,  house,  38,  39,  40. 

Census   methods,  47. 

Coloration,  4,  5,  6. 

Courtship,  10. 

cupido,  Tympanuchus,  1. 

Development  of  young,  16. 
Disease,  36. 

Disintegration,  family,  19. 
Distribution,  2,   (map)  3,  7. 
Drainage,  effect  of,  43. 

Eagle,   bald,  39. 

Flocking,  20. 
Floods,  35. 
Food,  25. 

Goshawk,   39. 

Grouse,  39. 

Growth   of  young,   16. 

Habitat,  30. 

control,   recommendations,   56. 

improvement,   46. 

requirements,  30. 
Hawk,  duck,  39. 

ferruginous  roughlegged,  39. 

Krider's,  39. 

marsh,  39. 

rough-legged,  39. 
Heath-hen,  1. 
Hunting,  effects,  44. 

Increase,  20. 


Limiting  factors,  31. 

Management,  45. 
Mating,   10. 
Mortality,  juvenile,  19. 

Nesting,  14. 

Nests,  predation  on,  37. 

Overgrazing,  effect  of,  42. 

pallidicinctus,  Tympanuchus,  4. 
Pasture  burning,  effect  of,  41. 

mowing,  43. 
Population  status,  8. 
Prairie  chicken,  Attwater's,  1. 

greater,  4. 

lesser,  4,  5. 
Predation,  37. 
Predator  control,  57. 
Protection,  45. 

Quail,  39. 

Rainfall,  32. 
Restocking,  58. 

Seasonal  movements,  21. 
Sparrow,  English,  17. 
Starling,  17. 
Storms,  35,  36. 
Surplus,  57. 

Turkey,  bronze,  17. 

Tympanuchus  cupido  americanus,  4. 

cupido  attwateri,  1,  4. 

cupido  cupido,  1. 

pallidicinctus,  4. 

Weight,  5. 
Wolf,  red,  38. 
Woody  vegetation,  36. 

Young,  development  of,  16. 
predation  on,  38, 


o 


65 


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